diff --git a/src/chatlog/content/filetransferwidget.cpp b/src/chatlog/content/filetransferwidget.cpp
index 60eaad726..ceba1b2b2 100644
--- a/src/chatlog/content/filetransferwidget.cpp
+++ b/src/chatlog/content/filetransferwidget.cpp
@@ -21,6 +21,7 @@
 #include "ui_filetransferwidget.h"
 
 #include "src/core/core.h"
+#include "src/core/corefile.h"
 #include "src/persistence/settings.h"
 #include "src/widget/gui.h"
 #include "src/widget/style.h"
@@ -85,19 +86,21 @@ FileTransferWidget::FileTransferWidget(QWidget* parent, ToxFile file)
         update();
     });
 
-    connect(Core::getInstance(), &Core::fileTransferInfo, this,
+    CoreFile* coreFile = Core::getInstance()->getCoreFile();
+
+    connect(coreFile, &CoreFile::fileTransferInfo, this,
             &FileTransferWidget::onFileTransferInfo);
-    connect(Core::getInstance(), &Core::fileTransferAccepted, this,
+    connect(coreFile, &CoreFile::fileTransferAccepted, this,
             &FileTransferWidget::onFileTransferAccepted);
-    connect(Core::getInstance(), &Core::fileTransferCancelled, this,
+    connect(coreFile, &CoreFile::fileTransferCancelled, this,
             &FileTransferWidget::onFileTransferCancelled);
-    connect(Core::getInstance(), &Core::fileTransferPaused, this,
+    connect(coreFile, &CoreFile::fileTransferPaused, this,
             &FileTransferWidget::onFileTransferPaused);
-    connect(Core::getInstance(), &Core::fileTransferFinished, this,
+    connect(coreFile, &CoreFile::fileTransferFinished, this,
             &FileTransferWidget::onFileTransferFinished);
-    connect(Core::getInstance(), &Core::fileTransferRemotePausedUnpaused, this,
+    connect(coreFile, &CoreFile::fileTransferRemotePausedUnpaused, this,
             &FileTransferWidget::fileTransferRemotePausedUnpaused);
-    connect(Core::getInstance(), &Core::fileTransferBrokenUnbroken, this,
+    connect(coreFile, &CoreFile::fileTransferBrokenUnbroken, this,
             &FileTransferWidget::fileTransferBrokenUnbroken);
     connect(ui->leftButton, &QPushButton::clicked, this, &FileTransferWidget::onLeftButtonClicked);
     connect(ui->rightButton, &QPushButton::clicked, this, &FileTransferWidget::onRightButtonClicked);
@@ -149,7 +152,8 @@ void FileTransferWidget::autoAcceptTransfer(const QString& path)
     // Do not automatically accept the file-transfer if the path is not writable.
     // The user can still accept it manually.
     if (tryRemoveFile(filepath)) {
-        Core::getInstance()->acceptFileRecvRequest(fileInfo.friendId, fileInfo.fileNum, filepath);
+        CoreFile* coreFile = Core::getInstance()->getCoreFile();
+        coreFile->acceptFileRecvRequest(fileInfo.friendId, fileInfo.fileNum, filepath);
     } else {
         qWarning() << "Cannot write to " << filepath;
     }
@@ -176,7 +180,8 @@ void FileTransferWidget::acceptTransfer(const QString& filepath)
     }
 
     // everything ok!
-    Core::getInstance()->acceptFileRecvRequest(fileInfo.friendId, fileInfo.fileNum, filepath);
+    CoreFile* coreFile = Core::getInstance()->getCoreFile();
+    coreFile->acceptFileRecvRequest(fileInfo.friendId, fileInfo.fileNum, filepath);
 }
 
 void FileTransferWidget::setBackgroundColor(const QColor& c, bool whiteFont)
@@ -464,7 +469,7 @@ void FileTransferWidget::updateSignals(ToxFile const& file)
     case ToxFile::BROKEN:
     case ToxFile::FINISHED:
         active = false;
-        disconnect(Core::getInstance(), nullptr, this, nullptr);
+        disconnect(Core::getInstance()->getCoreFile(), nullptr, this, nullptr);
         break;
     case ToxFile::INITIALIZING:
     case ToxFile::PAUSED:
@@ -553,22 +558,23 @@ void FileTransferWidget::setupButtons(ToxFile const& file)
 
 void FileTransferWidget::handleButton(QPushButton* btn)
 {
+    CoreFile* coreFile = Core::getInstance()->getCoreFile();
     if (fileInfo.direction == ToxFile::SENDING) {
         if (btn->objectName() == "cancel") {
-            Core::getInstance()->cancelFileSend(fileInfo.friendId, fileInfo.fileNum);
+            coreFile->cancelFileSend(fileInfo.friendId, fileInfo.fileNum);
         } else if (btn->objectName() == "pause") {
-            Core::getInstance()->pauseResumeFile(fileInfo.friendId, fileInfo.fileNum);
+            coreFile->pauseResumeFile(fileInfo.friendId, fileInfo.fileNum);
         } else if (btn->objectName() == "resume") {
-            Core::getInstance()->pauseResumeFile(fileInfo.friendId, fileInfo.fileNum);
+            coreFile->pauseResumeFile(fileInfo.friendId, fileInfo.fileNum);
         }
     } else // receiving or paused
     {
         if (btn->objectName() == "cancel") {
-            Core::getInstance()->cancelFileRecv(fileInfo.friendId, fileInfo.fileNum);
+            coreFile->cancelFileRecv(fileInfo.friendId, fileInfo.fileNum);
         } else if (btn->objectName() == "pause") {
-            Core::getInstance()->pauseResumeFile(fileInfo.friendId, fileInfo.fileNum);
+            coreFile->pauseResumeFile(fileInfo.friendId, fileInfo.fileNum);
         } else if (btn->objectName() == "resume") {
-            Core::getInstance()->pauseResumeFile(fileInfo.friendId, fileInfo.fileNum);
+            coreFile->pauseResumeFile(fileInfo.friendId, fileInfo.fileNum);
         } else if (btn->objectName() == "accept") {
             QString path =
                 QFileDialog::getSaveFileName(Q_NULLPTR,
diff --git a/src/core/core.cpp b/src/core/core.cpp
index 56eedca4a..8dcf757b8 100644
--- a/src/core/core.cpp
+++ b/src/core/core.cpp
@@ -165,10 +165,6 @@ void Core::registerCallbacks(Tox* tox)
     tox_callback_conference_peer_list_changed(tox, onGroupPeerListChange);
     tox_callback_conference_peer_name(tox, onGroupPeerNameChange);
     tox_callback_conference_title(tox, onGroupTitleChange);
-    tox_callback_file_chunk_request(tox, CoreFile::onFileDataCallback);
-    tox_callback_file_recv(tox, CoreFile::onFileReceiveCallback);
-    tox_callback_file_recv_chunk(tox, CoreFile::onFileRecvChunkCallback);
-    tox_callback_file_recv_control(tox, CoreFile::onFileControlCallback);
 }
 
 /**
@@ -293,6 +289,16 @@ ToxCorePtr Core::makeToxCore(const QByteArray& savedata, const ICoreSettings* co
         return {};
     }
 
+    // create CoreFile
+    core->file = CoreFile::makeCoreFile(core.get(), core->tox.get(), core->coreLoopLock);
+    if (!core->file) {
+        qCritical() << "CoreFile failed to start";
+        if (err) {
+            *err = ToxCoreErrors::FAILED_TO_START;
+        }
+        return {};
+    }
+
     registerCallbacks(core->tox.get());
 
     // connect the thread with the Core
@@ -359,6 +365,11 @@ CoreAV* Core::getAv()
     return av.get();
 }
 
+CoreFile* Core::getCoreFile() const
+{
+    return file.get();
+}
+
 /* Using the now commented out statements in checkConnection(), I watched how
  * many ticks disconnects-after-initial-connect lasted. Out of roughly 15 trials,
  * 5 disconnected; 4 were DCd for less than 20 ticks, while the 5th was ~50 ticks.
@@ -394,7 +405,7 @@ void Core::process()
     }
 
     unsigned sleeptime =
-        qMin(tox_iteration_interval(tox.get()), CoreFile::corefileIterationInterval());
+        qMin(tox_iteration_interval(tox.get()), getCoreFile()->corefileIterationInterval());
     toxTimer->start(sleeptime);
 }
 
@@ -513,15 +524,15 @@ void Core::onUserStatusChanged(Tox*, uint32_t friendId, Tox_User_Status userstat
     emit static_cast<Core*>(core)->friendStatusChanged(friendId, status);
 }
 
-void Core::onConnectionStatusChanged(Tox*, uint32_t friendId, Tox_Connection status, void* core)
+void Core::onConnectionStatusChanged(Tox*, uint32_t friendId, Tox_Connection status, void* vCore)
 {
+    Core* core = static_cast<Core*>(vCore);
     Status friendStatus = status != TOX_CONNECTION_NONE ? Status::Online : Status::Offline;
     // Ignore Online because it will be emited from onUserStatusChanged
     bool isOffline = friendStatus == Status::Offline;
     if (isOffline) {
-        emit static_cast<Core*>(core)->friendStatusChanged(friendId, friendStatus);
-        static_cast<Core*>(core)->checkLastOnline(friendId);
-        CoreFile::onConnectionStatusChanged(static_cast<Core*>(core), friendId, !isOffline);
+        emit core->friendStatusChanged(friendId, friendStatus);
+        core->checkLastOnline(friendId);
     }
 }
 
@@ -757,55 +768,6 @@ void Core::changeGroupTitle(int groupId, const QString& title)
     }
 }
 
-void Core::sendFile(uint32_t friendId, QString filename, QString filePath, long long filesize)
-{
-    QMutexLocker ml{&coreLoopLock};
-
-    CoreFile::sendFile(this, friendId, filename, filePath, filesize);
-}
-
-void Core::sendAvatarFile(uint32_t friendId, const QByteArray& data)
-{
-    QMutexLocker ml{&coreLoopLock};
-
-    CoreFile::sendAvatarFile(this, friendId, data);
-}
-
-void Core::pauseResumeFile(uint32_t friendId, uint32_t fileNum)
-{
-    QMutexLocker ml{&coreLoopLock};
-
-    CoreFile::pauseResumeFile(this, friendId, fileNum);
-}
-
-void Core::cancelFileSend(uint32_t friendId, uint32_t fileNum)
-{
-    QMutexLocker ml{&coreLoopLock};
-
-    CoreFile::cancelFileSend(this, friendId, fileNum);
-}
-
-void Core::cancelFileRecv(uint32_t friendId, uint32_t fileNum)
-{
-    QMutexLocker ml{&coreLoopLock};
-
-    CoreFile::cancelFileRecv(this, friendId, fileNum);
-}
-
-void Core::rejectFileRecvRequest(uint32_t friendId, uint32_t fileNum)
-{
-    QMutexLocker ml{&coreLoopLock};
-
-    CoreFile::rejectFileRecvRequest(this, friendId, fileNum);
-}
-
-void Core::acceptFileRecvRequest(uint32_t friendId, uint32_t fileNum, QString path)
-{
-    QMutexLocker ml{&coreLoopLock};
-
-    CoreFile::acceptFileRecvRequest(this, friendId, fileNum, path);
-}
-
 void Core::removeFriend(uint32_t friendId)
 {
     QMutexLocker ml{&coreLoopLock};
diff --git a/src/core/core.h b/src/core/core.h
index 9fef4cb89..898ab7a89 100644
--- a/src/core/core.h
+++ b/src/core/core.h
@@ -36,6 +36,7 @@
 #include <memory>
 
 class CoreAV;
+class CoreFile;
 class ICoreSettings;
 class GroupInvite;
 class Profile;
@@ -71,6 +72,7 @@ public:
     static Core* getInstance();
     const CoreAV* getAv() const;
     CoreAV* getAv();
+    CoreFile* getCoreFile() const;
     ~Core();
 
     static const QString TOX_EXT;
@@ -125,13 +127,6 @@ public slots:
     bool sendAction(uint32_t friendId, const QString& action, ReceiptNum& receipt);
     void sendTyping(uint32_t friendId, bool typing);
 
-    void sendAvatarFile(uint32_t friendId, const QByteArray& data);
-    void cancelFileSend(uint32_t friendId, uint32_t fileNum);
-    void cancelFileRecv(uint32_t friendId, uint32_t fileNum);
-    void rejectFileRecvRequest(uint32_t friendId, uint32_t fileNum);
-    void acceptFileRecvRequest(uint32_t friendId, uint32_t fileNum, QString path);
-    void pauseResumeFile(uint32_t friendId, uint32_t fileNum);
-
     void setNospam(uint32_t nospam);
 
 signals:
@@ -157,19 +152,6 @@ signals:
 
     void avReady();
 
-    void fileSendStarted(ToxFile file);
-    void fileReceiveRequested(ToxFile file);
-    void fileTransferAccepted(ToxFile file);
-    void fileTransferCancelled(ToxFile file);
-    void fileTransferFinished(ToxFile file);
-    void fileUploadFinished(const QString& path);
-    void fileDownloadFinished(const QString& path);
-    void fileTransferPaused(ToxFile file);
-    void fileTransferInfo(ToxFile file);
-    void fileTransferRemotePausedUnpaused(ToxFile file, bool paused);
-    void fileTransferBrokenUnbroken(ToxFile file, bool broken);
-    void fileNameChanged(const ToxPk& friendPk);
-
     void saveRequest();
 
     /**
@@ -204,8 +186,6 @@ signals:
 
     void failedToRemoveFriend(uint32_t friendId);
 
-    void fileSendFailed(uint32_t friendId, const QString& fname);
-
 private:
     Core(QThread* coreThread);
 
@@ -221,7 +201,7 @@ private:
     static void onUserStatusChanged(Tox* tox, uint32_t friendId, Tox_User_Status userstatus,
                                     void* core);
     static void onConnectionStatusChanged(Tox* tox, uint32_t friendId, Tox_Connection status,
-                                          void* core);
+                                          void* vCore);
     static void onGroupInvite(Tox* tox, uint32_t friendId, Tox_Conference_Type type,
                               const uint8_t* cookie, size_t length, void* vCore);
     static void onGroupMessage(Tox* tox, uint32_t groupId, uint32_t peerId, Tox_Message_Type type,
@@ -241,7 +221,6 @@ private:
 
     void checkEncryptedHistory();
     void makeTox(QByteArray savedata, ICoreSettings* s);
-    void makeAv();
     void loadFriends();
     void loadGroups();
     void bootstrapDht();
@@ -267,6 +246,7 @@ private:
     using ToxPtr = std::unique_ptr<Tox, ToxDeleter>;
     ToxPtr tox;
 
+    std::unique_ptr<CoreFile> file;
     std::unique_ptr<CoreAV> av;
     QTimer* toxTimer = nullptr;
     // recursive, since we might call our own functions
@@ -275,7 +255,6 @@ private:
     std::unique_ptr<QThread> coreThread = nullptr;
 
     friend class Audio;    ///< Audio can access our calls directly to reduce latency
-    friend class CoreFile; ///< CoreFile can access tox* and emit our signals
     friend class CoreAV;   ///< CoreAV accesses our toxav* for now
 };
 
diff --git a/src/core/corefile.cpp b/src/core/corefile.cpp
index 64949c7d0..0f116cde4 100644
--- a/src/core/corefile.cpp
+++ b/src/core/corefile.cpp
@@ -22,25 +22,36 @@
 #include "core.h"
 #include "toxfile.h"
 #include "toxstring.h"
-#include "src/persistence/profile.h"
 #include "src/persistence/settings.h"
 #include <QDebug>
 #include <QDir>
 #include <QFile>
 #include <QRegularExpression>
 #include <QThread>
+#include <cassert>
 #include <memory>
 
 /**
  * @class CoreFile
- * @brief Implements Core's file transfer callbacks.
- *
- * Avoids polluting core.h with private internal callbacks.
+ * @brief Manages the file transfer service of toxcore
  */
 
-QMutex CoreFile::fileSendMutex;
-QHash<uint64_t, ToxFile> CoreFile::fileMap;
-using namespace std;
+CoreFilePtr CoreFile::makeCoreFile(Core *core, Tox *tox, QMutex &coreLoopLock)
+{
+    assert(core != nullptr);
+    assert(tox != nullptr);
+    connectCallbacks(*tox);
+    CoreFilePtr result = CoreFilePtr{new CoreFile{tox, coreLoopLock}};
+    connect(core, &Core::friendStatusChanged, result.get(), &CoreFile::onConnectionStatusChanged);
+
+    return result;
+}
+
+CoreFile::CoreFile(Tox *core, QMutex &coreLoopLock)
+    : tox{core}
+    , coreLoopLock{&coreLoopLock}
+{
+}
 
 /**
  * @brief Get corefile iteration interval.
@@ -66,12 +77,21 @@ unsigned CoreFile::corefileIterationInterval()
     return idleInterval;
 }
 
-void CoreFile::sendAvatarFile(Core* core, uint32_t friendId, const QByteArray& data)
+void CoreFile::connectCallbacks(Tox &tox)
 {
-    QMutexLocker mlocker(&fileSendMutex);
+    // be careful not to to reconnect already used callbacks here
+    tox_callback_file_chunk_request(&tox, CoreFile::onFileDataCallback);
+    tox_callback_file_recv(&tox, CoreFile::onFileReceiveCallback);
+    tox_callback_file_recv_chunk(&tox, CoreFile::onFileRecvChunkCallback);
+    tox_callback_file_recv_control(&tox, CoreFile::onFileControlCallback);
+}
+
+void CoreFile::sendAvatarFile(uint32_t friendId, const QByteArray& data)
+{
+    QMutexLocker{coreLoopLock};
 
     if (data.isEmpty()) {
-        tox_file_send(core->tox.get(), friendId, TOX_FILE_KIND_AVATAR, 0, nullptr, nullptr, 0, nullptr);
+        tox_file_send(tox, friendId, TOX_FILE_KIND_AVATAR, 0, nullptr, nullptr, 0, nullptr);
         return;
     }
 
@@ -81,7 +101,7 @@ void CoreFile::sendAvatarFile(Core* core, uint32_t friendId, const QByteArray& d
     uint64_t filesize = data.size();
 
     Tox_Err_File_Send error;
-    uint32_t fileNum = tox_file_send(core->tox.get(), friendId, TOX_FILE_KIND_AVATAR, filesize,
+    uint32_t fileNum = tox_file_send(tox, friendId, TOX_FILE_KIND_AVATAR, filesize,
                                      avatarHash, avatarHash, TOX_HASH_LENGTH, &error);
 
     switch (error) {
@@ -111,22 +131,23 @@ void CoreFile::sendAvatarFile(Core* core, uint32_t friendId, const QByteArray& d
     file.fileKind = TOX_FILE_KIND_AVATAR;
     file.avatarData = data;
     file.resumeFileId.resize(TOX_FILE_ID_LENGTH);
-    tox_file_get_file_id(core->tox.get(), friendId, fileNum, (uint8_t*)file.resumeFileId.data(),
+    tox_file_get_file_id(tox, friendId, fileNum, (uint8_t*)file.resumeFileId.data(),
                          nullptr);
     addFile(friendId, fileNum, file);
 }
 
-void CoreFile::sendFile(Core* core, uint32_t friendId, QString filename, QString filePath,
+void CoreFile::sendFile(uint32_t friendId, QString filename, QString filePath,
                         long long filesize)
 {
-    QMutexLocker mlocker(&fileSendMutex);
+    QMutexLocker{coreLoopLock};
+
     ToxString fileName(filename);
     TOX_ERR_FILE_SEND sendErr;
-    uint32_t fileNum = tox_file_send(core->tox.get(), friendId, TOX_FILE_KIND_DATA, filesize,
+    uint32_t fileNum = tox_file_send(tox, friendId, TOX_FILE_KIND_DATA, filesize,
                                      nullptr, fileName.data(), fileName.size(), &sendErr);
     if (sendErr != TOX_ERR_FILE_SEND_OK) {
         qWarning() << "sendFile: Can't create the Tox file sender (" << sendErr << ")";
-        emit core->fileSendFailed(friendId, fileName.getQString());
+        emit fileSendFailed(friendId, fileName.getQString());
         return;
     }
     qDebug() << QString("sendFile: Created file sender %1 with friend %2").arg(fileNum).arg(friendId);
@@ -134,7 +155,7 @@ void CoreFile::sendFile(Core* core, uint32_t friendId, QString filename, QString
     ToxFile file{fileNum, friendId, fileName.getQString(), filePath, ToxFile::SENDING};
     file.filesize = filesize;
     file.resumeFileId.resize(TOX_FILE_ID_LENGTH);
-    tox_file_get_file_id(core->tox.get(), friendId, fileNum, (uint8_t*)file.resumeFileId.data(),
+    tox_file_get_file_id(tox, friendId, fileNum, (uint8_t*)file.resumeFileId.data(),
                          nullptr);
     if (!file.open(false)) {
         qWarning() << QString("sendFile: Can't open file, error: %1").arg(file.file->errorString());
@@ -142,11 +163,13 @@ void CoreFile::sendFile(Core* core, uint32_t friendId, QString filename, QString
 
     addFile(friendId, fileNum, file);
 
-    emit core->fileSendStarted(file);
+    emit fileSendStarted(file);
 }
 
-void CoreFile::pauseResumeFile(Core* core, uint32_t friendId, uint32_t fileId)
+void CoreFile::pauseResumeFile(uint32_t friendId, uint32_t fileId)
 {
+    QMutexLocker{coreLoopLock};
+
     ToxFile* file = findFile(friendId, fileId);
     if (!file) {
         qWarning("pauseResumeFileSend: No such file in queue");
@@ -162,23 +185,25 @@ void CoreFile::pauseResumeFile(Core* core, uint32_t friendId, uint32_t fileId)
 
     if (file->pauseStatus.paused()) {
         file->status = ToxFile::PAUSED;
-        emit core->fileTransferPaused(*file);
+        emit fileTransferPaused(*file);
     } else {
         file->status = ToxFile::TRANSMITTING;
-        emit core->fileTransferAccepted(*file);
+        emit fileTransferAccepted(*file);
     }
 
     if (file->pauseStatus.localPaused()) {
-        tox_file_control(core->tox.get(), file->friendId, file->fileNum, TOX_FILE_CONTROL_PAUSE,
+        tox_file_control(tox, file->friendId, file->fileNum, TOX_FILE_CONTROL_PAUSE,
                          nullptr);
     } else {
-        tox_file_control(core->tox.get(), file->friendId, file->fileNum, TOX_FILE_CONTROL_RESUME,
+        tox_file_control(tox, file->friendId, file->fileNum, TOX_FILE_CONTROL_RESUME,
                          nullptr);
     }
 }
 
-void CoreFile::cancelFileSend(Core* core, uint32_t friendId, uint32_t fileId)
+void CoreFile::cancelFileSend(uint32_t friendId, uint32_t fileId)
 {
+    QMutexLocker{coreLoopLock};
+
     ToxFile* file = findFile(friendId, fileId);
     if (!file) {
         qWarning("cancelFileSend: No such file in queue");
@@ -186,39 +211,45 @@ void CoreFile::cancelFileSend(Core* core, uint32_t friendId, uint32_t fileId)
     }
 
     file->status = ToxFile::CANCELED;
-    emit core->fileTransferCancelled(*file);
-    tox_file_control(core->tox.get(), file->friendId, file->fileNum, TOX_FILE_CONTROL_CANCEL, nullptr);
+    emit fileTransferCancelled(*file);
+    tox_file_control(tox, file->friendId, file->fileNum, TOX_FILE_CONTROL_CANCEL, nullptr);
     removeFile(friendId, fileId);
 }
 
-void CoreFile::cancelFileRecv(Core* core, uint32_t friendId, uint32_t fileId)
+void CoreFile::cancelFileRecv(uint32_t friendId, uint32_t fileId)
 {
+    QMutexLocker{coreLoopLock};
+
     ToxFile* file = findFile(friendId, fileId);
     if (!file) {
         qWarning("cancelFileRecv: No such file in queue");
         return;
     }
     file->status = ToxFile::CANCELED;
-    emit core->fileTransferCancelled(*file);
-    tox_file_control(core->tox.get(), file->friendId, file->fileNum, TOX_FILE_CONTROL_CANCEL, nullptr);
+    emit fileTransferCancelled(*file);
+    tox_file_control(tox, file->friendId, file->fileNum, TOX_FILE_CONTROL_CANCEL, nullptr);
     removeFile(friendId, fileId);
 }
 
-void CoreFile::rejectFileRecvRequest(Core* core, uint32_t friendId, uint32_t fileId)
+void CoreFile::rejectFileRecvRequest(uint32_t friendId, uint32_t fileId)
 {
+    QMutexLocker{coreLoopLock};
+
     ToxFile* file = findFile(friendId, fileId);
     if (!file) {
         qWarning("rejectFileRecvRequest: No such file in queue");
         return;
     }
     file->status = ToxFile::CANCELED;
-    emit core->fileTransferCancelled(*file);
-    tox_file_control(core->tox.get(), file->friendId, file->fileNum, TOX_FILE_CONTROL_CANCEL, nullptr);
+    emit fileTransferCancelled(*file);
+    tox_file_control(tox, file->friendId, file->fileNum, TOX_FILE_CONTROL_CANCEL, nullptr);
     removeFile(friendId, fileId);
 }
 
-void CoreFile::acceptFileRecvRequest(Core* core, uint32_t friendId, uint32_t fileId, QString path)
+void CoreFile::acceptFileRecvRequest(uint32_t friendId, uint32_t fileId, QString path)
 {
+    QMutexLocker{coreLoopLock};
+
     ToxFile* file = findFile(friendId, fileId);
     if (!file) {
         qWarning("acceptFileRecvRequest: No such file in queue");
@@ -230,12 +261,14 @@ void CoreFile::acceptFileRecvRequest(Core* core, uint32_t friendId, uint32_t fil
         return;
     }
     file->status = ToxFile::TRANSMITTING;
-    emit core->fileTransferAccepted(*file);
-    tox_file_control(core->tox.get(), file->friendId, file->fileNum, TOX_FILE_CONTROL_RESUME, nullptr);
+    emit fileTransferAccepted(*file);
+    tox_file_control(tox, file->friendId, file->fileNum, TOX_FILE_CONTROL_RESUME, nullptr);
 }
 
 ToxFile* CoreFile::findFile(uint32_t friendId, uint32_t fileId)
 {
+    QMutexLocker{coreLoopLock};
+
     uint64_t key = getFriendKey(friendId, fileId);
     if (fileMap.contains(key)) {
         return &fileMap[key];
@@ -276,11 +309,12 @@ QString CoreFile::getCleanFileName(QString filename)
     return filename;
 }
 
-void CoreFile::onFileReceiveCallback(Tox*, uint32_t friendId, uint32_t fileId, uint32_t kind,
+void CoreFile::onFileReceiveCallback(Tox* tox, uint32_t friendId, uint32_t fileId, uint32_t kind,
                                      uint64_t filesize, const uint8_t* fname, size_t fnameLen,
                                      void* vCore)
 {
     Core* core = static_cast<Core*>(vCore);
+    CoreFile* coreFile = core->getCoreFile();
     auto filename = ToxString(fname, fnameLen);
     const ToxPk friendPk = core->getFriendPublicKey(friendId);
 
@@ -294,7 +328,7 @@ void CoreFile::onFileReceiveCallback(Tox*, uint32_t friendId, uint32_t fileId, u
             static_assert(TOX_HASH_LENGTH <= TOX_FILE_ID_LENGTH,
                           "TOX_HASH_LENGTH > TOX_FILE_ID_LENGTH!");
             uint8_t avatarHash[TOX_FILE_ID_LENGTH];
-            tox_file_get_file_id(core->tox.get(), friendId, fileId, avatarHash, nullptr);
+            tox_file_get_file_id(tox, friendId, fileId, avatarHash, nullptr);
             QByteArray avatarBytes{static_cast<const char*>(static_cast<const void*>(avatarHash)),
                                    TOX_HASH_LENGTH};
             emit core->fileAvatarOfferReceived(friendId, fileId, avatarBytes);
@@ -305,7 +339,7 @@ void CoreFile::onFileReceiveCallback(Tox*, uint32_t friendId, uint32_t fileId, u
         if (cleanFileName != filename.getQString()) {
             qDebug() << QStringLiteral("Cleaned filename");
             filename = ToxString(cleanFileName);
-            emit core->fileNameChanged(friendPk);
+            emit coreFile->fileNameChanged(friendPk);
         } else {
             qDebug() << QStringLiteral("filename already clean");
         }
@@ -316,24 +350,23 @@ void CoreFile::onFileReceiveCallback(Tox*, uint32_t friendId, uint32_t fileId, u
     file.filesize = filesize;
     file.fileKind = kind;
     file.resumeFileId.resize(TOX_FILE_ID_LENGTH);
-    tox_file_get_file_id(core->tox.get(), friendId, fileId, (uint8_t*)file.resumeFileId.data(),
+    tox_file_get_file_id(tox, friendId, fileId, (uint8_t*)file.resumeFileId.data(),
                          nullptr);
-    addFile(friendId, fileId, file);
-    if (kind != TOX_FILE_KIND_AVATAR)
-        emit core->fileReceiveRequested(file);
+    coreFile->addFile(friendId, fileId, file);
+    if (kind != TOX_FILE_KIND_AVATAR) {
+        emit coreFile->fileReceiveRequested(file);
+    }
 }
 
 // TODO(sudden6): This whole method is a mess but needed to get stuff working for now
 void CoreFile::handleAvatarOffer(uint32_t friendId, uint32_t fileId, bool accept)
 {
-    // TODO(sudden6): evil evil evil
-    auto core = Core::getInstance();
     if (!accept) {
         // If it's an avatar but we already have it cached, cancel
         qDebug() << QString("Received avatar request %1:%2, reject, since we have it in cache.")
                         .arg(friendId)
                         .arg(fileId);
-        tox_file_control(core->tox.get(), friendId, fileId, TOX_FILE_CONTROL_CANCEL, nullptr);
+        tox_file_control(tox, friendId, fileId, TOX_FILE_CONTROL_CANCEL, nullptr);
         return;
     }
 
@@ -342,21 +375,23 @@ void CoreFile::handleAvatarOffer(uint32_t friendId, uint32_t fileId, bool accept
                         "in cache.")
                     .arg(friendId)
                     .arg(fileId);
-    tox_file_control(core->tox.get(), friendId, fileId, TOX_FILE_CONTROL_RESUME, nullptr);
+    tox_file_control(tox, friendId, fileId, TOX_FILE_CONTROL_RESUME, nullptr);
 
     ToxFile file{fileId, friendId, "<avatar>", "", ToxFile::RECEIVING};
     file.filesize = 0;
     file.fileKind = TOX_FILE_KIND_AVATAR;
     file.resumeFileId.resize(TOX_FILE_ID_LENGTH);
-    tox_file_get_file_id(core->tox.get(), friendId, fileId, (uint8_t*)file.resumeFileId.data(),
+    tox_file_get_file_id(tox, friendId, fileId, (uint8_t*)file.resumeFileId.data(),
                          nullptr);
     addFile(friendId, fileId, file);
 }
 
 void CoreFile::onFileControlCallback(Tox*, uint32_t friendId, uint32_t fileId,
-                                     Tox_File_Control control, void* core)
+                                     Tox_File_Control control, void* vCore)
 {
-    ToxFile* file = findFile(friendId, fileId);
+    Core* core = static_cast<Core*>(vCore);
+    CoreFile* coreFile = core->getCoreFile();
+    ToxFile* file = coreFile->findFile(friendId, fileId);
     if (!file) {
         qWarning("onFileControlCallback: No such file in queue");
         return;
@@ -366,13 +401,13 @@ void CoreFile::onFileControlCallback(Tox*, uint32_t friendId, uint32_t fileId,
         if (file->fileKind != TOX_FILE_KIND_AVATAR)
             qDebug() << "File tranfer" << friendId << ":" << fileId << "cancelled by friend";
         file->status = ToxFile::CANCELED;
-        emit static_cast<Core*>(core)->fileTransferCancelled(*file);
-        removeFile(friendId, fileId);
+        emit coreFile->fileTransferCancelled(*file);
+        coreFile->removeFile(friendId, fileId);
     } else if (control == TOX_FILE_CONTROL_PAUSE) {
         qDebug() << "onFileControlCallback: Received pause for file " << friendId << ":" << fileId;
         file->pauseStatus.remotePause();
         file->status = ToxFile::PAUSED;
-        emit static_cast<Core*>(core)->fileTransferRemotePausedUnpaused(*file, true);
+        emit coreFile->fileTransferRemotePausedUnpaused(*file, true);
     } else if (control == TOX_FILE_CONTROL_RESUME) {
         if (file->direction == ToxFile::SENDING && file->fileKind == TOX_FILE_KIND_AVATAR)
             qDebug() << "Avatar transfer" << fileId << "to friend" << friendId << "accepted";
@@ -380,17 +415,19 @@ void CoreFile::onFileControlCallback(Tox*, uint32_t friendId, uint32_t fileId,
             qDebug() << "onFileControlCallback: Received resume for file " << friendId << ":" << fileId;
         file->pauseStatus.remoteResume();
         file->status = file->pauseStatus.paused() ? ToxFile::PAUSED : ToxFile::TRANSMITTING;
-        emit static_cast<Core*>(core)->fileTransferRemotePausedUnpaused(*file, false);
+        emit coreFile->fileTransferRemotePausedUnpaused(*file, false);
     } else {
         qWarning() << "Unhandled file control " << control << " for file " << friendId << ':' << fileId;
     }
 }
 
 void CoreFile::onFileDataCallback(Tox* tox, uint32_t friendId, uint32_t fileId, uint64_t pos,
-                                  size_t length, void* core)
+                                  size_t length, void* vCore)
 {
 
-    ToxFile* file = findFile(friendId, fileId);
+    Core* core = static_cast<Core*>(vCore);
+    CoreFile* coreFile = core->getCoreFile();
+    ToxFile* file = coreFile->findFile(friendId, fileId);
     if (!file) {
         qWarning("onFileDataCallback: No such file in queue");
         return;
@@ -400,14 +437,14 @@ void CoreFile::onFileDataCallback(Tox* tox, uint32_t friendId, uint32_t fileId,
     if (!length) {
         file->status = ToxFile::FINISHED;
         if (file->fileKind != TOX_FILE_KIND_AVATAR) {
-            emit static_cast<Core*>(core)->fileTransferFinished(*file);
-            emit static_cast<Core*>(core)->fileUploadFinished(file->filePath);
+            emit coreFile->fileTransferFinished(*file);
+            emit coreFile->fileUploadFinished(file->filePath);
         }
-        removeFile(friendId, fileId);
+        coreFile->removeFile(friendId, fileId);
         return;
     }
 
-    unique_ptr<uint8_t[]> data(new uint8_t[length]);
+    std::unique_ptr<uint8_t[]> data(new uint8_t[length]);
     int64_t nread;
 
     if (file->fileKind == TOX_FILE_KIND_AVATAR) {
@@ -420,9 +457,9 @@ void CoreFile::onFileDataCallback(Tox* tox, uint32_t friendId, uint32_t fileId,
         if (nread <= 0) {
             qWarning("onFileDataCallback: Failed to read from file");
             file->status = ToxFile::CANCELED;
-            emit static_cast<Core*>(core)->fileTransferCancelled(*file);
+            emit coreFile->fileTransferCancelled(*file);
             tox_file_send_chunk(tox, friendId, fileId, pos, nullptr, 0, nullptr);
-            removeFile(friendId, fileId);
+            coreFile->removeFile(friendId, fileId);
             return;
         }
         file->bytesSent += length;
@@ -433,15 +470,17 @@ void CoreFile::onFileDataCallback(Tox* tox, uint32_t friendId, uint32_t fileId,
         qWarning("onFileDataCallback: Failed to send data chunk");
         return;
     }
-    if (file->fileKind != TOX_FILE_KIND_AVATAR)
-        emit static_cast<Core*>(core)->fileTransferInfo(*file);
+    if (file->fileKind != TOX_FILE_KIND_AVATAR) {
+        emit coreFile->fileTransferInfo(*file);
+    }
 }
 
 void CoreFile::onFileRecvChunkCallback(Tox* tox, uint32_t friendId, uint32_t fileId, uint64_t position,
                                        const uint8_t* data, size_t length, void* vCore)
 {
     Core* core = static_cast<Core*>(vCore);
-    ToxFile* file = findFile(friendId, fileId);
+    CoreFile* coreFile = core->getCoreFile();
+    ToxFile* file = coreFile->findFile(friendId, fileId);
     if (!file) {
         qWarning("onFileRecvChunkCallback: No such file in queue");
         tox_file_control(tox, friendId, fileId, TOX_FILE_CONTROL_CANCEL, nullptr);
@@ -452,10 +491,10 @@ void CoreFile::onFileRecvChunkCallback(Tox* tox, uint32_t friendId, uint32_t fil
         qWarning("onFileRecvChunkCallback: Received a chunk out-of-order, aborting transfer");
         if (file->fileKind != TOX_FILE_KIND_AVATAR) {
             file->status = ToxFile::CANCELED;
-            emit core->fileTransferCancelled(*file);
+            emit coreFile->fileTransferCancelled(*file);
         }
         tox_file_control(tox, friendId, fileId, TOX_FILE_CONTROL_CANCEL, nullptr);
-        removeFile(friendId, fileId);
+        coreFile->removeFile(friendId, fileId);
         return;
     }
 
@@ -469,26 +508,29 @@ void CoreFile::onFileRecvChunkCallback(Tox* tox, uint32_t friendId, uint32_t fil
                 emit core->friendAvatarChanged(core->getFriendPublicKey(friendId), file->avatarData);
             }
         } else {
-            emit core->fileTransferFinished(*file);
-            emit core->fileDownloadFinished(file->filePath);
+            emit coreFile->fileTransferFinished(*file);
+            emit coreFile->fileDownloadFinished(file->filePath);
         }
-        removeFile(friendId, fileId);
+        coreFile->removeFile(friendId, fileId);
         return;
     }
 
-    if (file->fileKind == TOX_FILE_KIND_AVATAR)
+    if (file->fileKind == TOX_FILE_KIND_AVATAR) {
         file->avatarData.append((char*)data, length);
-    else
+    } else {
         file->file->write((char*)data, length);
+    }
     file->bytesSent += length;
     file->hashGenerator->addData((const char*)data, length);
 
-    if (file->fileKind != TOX_FILE_KIND_AVATAR)
-        emit static_cast<Core*>(core)->fileTransferInfo(*file);
+    if (file->fileKind != TOX_FILE_KIND_AVATAR) {
+        emit coreFile->fileTransferInfo(*file);
+    }
 }
 
-void CoreFile::onConnectionStatusChanged(Core* core, uint32_t friendId, bool online)
+void CoreFile::onConnectionStatusChanged(uint32_t friendId, Status state)
 {
+    bool isOffline = state == Status::Offline;
     // TODO: Actually resume broken file transfers
     // We need to:
     // - Start a new file transfer with the same 32byte file ID with toxcore
@@ -496,11 +538,11 @@ void CoreFile::onConnectionStatusChanged(Core* core, uint32_t friendId, bool onl
     // - Update the fileNum in our ToxFile
     // - Update the users of our signals to check the 32byte tox file ID, not the uint32_t file_num
     // (fileId)
-    ToxFile::FileStatus status = online ? ToxFile::TRANSMITTING : ToxFile::BROKEN;
+    ToxFile::FileStatus status = !isOffline ? ToxFile::TRANSMITTING : ToxFile::BROKEN;
     for (uint64_t key : fileMap.keys()) {
         if (key >> 32 != friendId)
             continue;
         fileMap[key].status = status;
-        emit core->fileTransferBrokenUnbroken(fileMap[key], !online);
+        emit fileTransferBrokenUnbroken(fileMap[key], !isOffline);
     }
 }
diff --git a/src/core/corefile.h b/src/core/corefile.h
index f45b29de3..e38459d1e 100644
--- a/src/core/corefile.h
+++ b/src/core/corefile.h
@@ -27,60 +27,85 @@
 #include <tox/tox.h>
 
 #include "toxfile.h"
+#include "src/core/core.h"
+#include "src/core/toxpk.h"
 
 #include <QHash>
 #include <QMutex>
+#include <QObject>
 #include <QString>
 
 struct Tox;
-class Core;
+class CoreFile;
 
-class CoreFile
+using CoreFilePtr = std::unique_ptr<CoreFile>;
+
+class CoreFile : public QObject
 {
-    friend class Core;
-
+    Q_OBJECT
 
 public:
-    static void handleAvatarOffer(uint32_t friendId, uint32_t fileId, bool accept);
+    void handleAvatarOffer(uint32_t friendId, uint32_t fileId, bool accept);
+    static CoreFilePtr makeCoreFile(Core* core, Tox* tox, QMutex& coreLoopLock);
 
-private:
-    CoreFile() = delete;
-
-    // Internal file sending APIs, used by Core. Public API in core.h
-private:
-    static void sendFile(Core* core, uint32_t friendId, QString filename, QString filePath,
+    void sendFile(uint32_t friendId, QString filename, QString filePath,
                          long long filesize);
-    static void sendAvatarFile(Core* core, uint32_t friendId, const QByteArray& data);
-    static void pauseResumeFile(Core* core, uint32_t friendId, uint32_t fileId);
-    static void cancelFileSend(Core* core, uint32_t friendId, uint32_t fileId);
-    static void cancelFileRecv(Core* core, uint32_t friendId, uint32_t fileId);
-    static void rejectFileRecvRequest(Core* core, uint32_t friendId, uint32_t fileId);
-    static void acceptFileRecvRequest(Core* core, uint32_t friendId, uint32_t fileId, QString path);
-    static ToxFile* findFile(uint32_t friendId, uint32_t fileId);
-    static void addFile(uint32_t friendId, uint32_t fileId, const ToxFile& file);
-    static void removeFile(uint32_t friendId, uint32_t fileId);
-    static unsigned corefileIterationInterval();
+    void sendAvatarFile(uint32_t friendId, const QByteArray& data);
+    void pauseResumeFile(uint32_t friendId, uint32_t fileId);
+    void cancelFileSend(uint32_t friendId, uint32_t fileId);
+
+    void cancelFileRecv(uint32_t friendId, uint32_t fileId);
+    void rejectFileRecvRequest(uint32_t friendId, uint32_t fileId);
+    void acceptFileRecvRequest(uint32_t friendId, uint32_t fileId, QString path);
+
+    unsigned corefileIterationInterval();
+
+signals:
+    void fileSendStarted(ToxFile file);
+    void fileReceiveRequested(ToxFile file);
+    void fileTransferAccepted(ToxFile file);
+    void fileTransferCancelled(ToxFile file);
+    void fileTransferFinished(ToxFile file);
+    void fileUploadFinished(const QString& path);
+    void fileDownloadFinished(const QString& path);
+    void fileTransferPaused(ToxFile file);
+    void fileTransferInfo(ToxFile file);
+    void fileTransferRemotePausedUnpaused(ToxFile file, bool paused);
+    void fileTransferBrokenUnbroken(ToxFile file, bool broken);
+    void fileNameChanged(const ToxPk& friendPk);
+    void fileSendFailed(uint32_t friendId, const QString& fname);
+
+private:
+    CoreFile(Tox* core, QMutex& coreLoopLock);
+
+    ToxFile* findFile(uint32_t friendId, uint32_t fileId);
+    void addFile(uint32_t friendId, uint32_t fileId, const ToxFile& file);
+    void removeFile(uint32_t friendId, uint32_t fileId);
     static constexpr uint64_t getFriendKey(uint32_t friendId, uint32_t fileId)
     {
         return (static_cast<std::uint64_t>(friendId) << 32) + fileId;
     }
 
-private:
-    static void onFileReceiveCallback(Tox*, uint32_t friendId, uint32_t fileId, uint32_t kind,
+    static void connectCallbacks(Tox& tox);
+    static void onFileReceiveCallback(Tox* tox, uint32_t friendId, uint32_t fileId, uint32_t kind,
                                       uint64_t filesize, const uint8_t* fname, size_t fnameLen,
                                       void* vCore);
     static void onFileControlCallback(Tox* tox, uint32_t friendId, uint32_t fileId,
-                                      Tox_File_Control control, void* core);
+                                      Tox_File_Control control, void* vCore);
     static void onFileDataCallback(Tox* tox, uint32_t friendId, uint32_t fileId, uint64_t pos,
-                                   size_t length, void* core);
+                                   size_t length, void* vCore);
     static void onFileRecvChunkCallback(Tox* tox, uint32_t friendId, uint32_t fileId, uint64_t position,
                                         const uint8_t* data, size_t length, void* vCore);
-    static void onConnectionStatusChanged(Core* core, uint32_t friendId, bool online);
+
+    static QString getCleanFileName(QString filename);
+
+private slots:
+    void onConnectionStatusChanged(uint32_t friendId, Status state);
 
 private:
-    static QMutex fileSendMutex;
-    static QHash<uint64_t, ToxFile> fileMap;
-    static QString getCleanFileName(QString filename);
+    QHash<uint64_t, ToxFile> fileMap;
+    Tox* tox;
+    QMutex* coreLoopLock = nullptr;
 };
 
 #endif // COREFILE_H
diff --git a/src/net/avatarbroadcaster.cpp b/src/net/avatarbroadcaster.cpp
index 75fdc6394..39eaaab4d 100644
--- a/src/net/avatarbroadcaster.cpp
+++ b/src/net/avatarbroadcaster.cpp
@@ -20,6 +20,7 @@
 
 #include "avatarbroadcaster.h"
 #include "src/core/core.h"
+#include "src/core/corefile.h"
 #include <QDebug>
 #include <QObject>
 
@@ -66,7 +67,8 @@ void AvatarBroadcaster::sendAvatarTo(uint32_t friendId)
         return;
     if (!Core::getInstance()->isFriendOnline(friendId))
         return;
-    Core::getInstance()->sendAvatarFile(friendId, avatarData);
+    CoreFile* coreFile = Core::getInstance()->getCoreFile();
+    coreFile->sendAvatarFile(friendId, avatarData);
     friendsSentTo[friendId] = true;
 }
 
diff --git a/src/persistence/profile.cpp b/src/persistence/profile.cpp
index 82ee49d83..7dc50464a 100644
--- a/src/persistence/profile.cpp
+++ b/src/persistence/profile.cpp
@@ -333,7 +333,7 @@ void Profile::onAvatarOfferReceived(uint32_t friendId, uint32_t fileId, const QB
 {
     // accept if we don't have it already
     const bool accept = getAvatarHash(core->getFriendPublicKey(friendId)) != avatarHash;
-    CoreFile::handleAvatarOffer(friendId, fileId, accept);
+    core->getCoreFile()->handleAvatarOffer(friendId, fileId, accept);
 }
 
 /**
diff --git a/src/widget/form/chatform.cpp b/src/widget/form/chatform.cpp
index 08c9a9777..7ce09de19 100644
--- a/src/widget/form/chatform.cpp
+++ b/src/widget/form/chatform.cpp
@@ -25,6 +25,7 @@
 #include "src/chatlog/content/text.h"
 #include "src/core/core.h"
 #include "src/core/coreav.h"
+#include "src/core/corefile.h"
 #include "src/model/friend.h"
 #include "src/nexus.h"
 #include "src/persistence/history.h"
@@ -160,18 +161,19 @@ ChatForm::ChatForm(Friend* chatFriend, History* history)
 
     const Core* core = Core::getInstance();
     const Profile* profile = Nexus::getProfile();
-    connect(core, &Core::fileReceiveRequested, this, &ChatForm::onFileRecvRequest);
+    const CoreFile* coreFile = core->getCoreFile();
+    connect(coreFile, &CoreFile::fileReceiveRequested, this, &ChatForm::onFileRecvRequest);
     connect(profile, &Profile::friendAvatarChanged, this, &ChatForm::onAvatarChanged);
-    connect(core, &Core::fileSendStarted, this, &ChatForm::startFileSend);
-    connect(core, &Core::fileTransferFinished, this, &ChatForm::onFileTransferFinished);
-    connect(core, &Core::fileTransferCancelled, this, &ChatForm::onFileTransferCancelled);
-    connect(core, &Core::fileTransferBrokenUnbroken, this, &ChatForm::onFileTransferBrokenUnbroken);
-    connect(core, &Core::fileSendFailed, this, &ChatForm::onFileSendFailed);
+    connect(coreFile, &CoreFile::fileSendStarted, this, &ChatForm::startFileSend);
+    connect(coreFile, &CoreFile::fileTransferFinished, this, &ChatForm::onFileTransferFinished);
+    connect(coreFile, &CoreFile::fileTransferCancelled, this, &ChatForm::onFileTransferCancelled);
+    connect(coreFile, &CoreFile::fileTransferBrokenUnbroken, this, &ChatForm::onFileTransferBrokenUnbroken);
+    connect(coreFile, &CoreFile::fileSendFailed, this, &ChatForm::onFileSendFailed);
     connect(core, &Core::receiptRecieved, this, &ChatForm::onReceiptReceived);
     connect(core, &Core::friendMessageReceived, this, &ChatForm::onFriendMessageReceived);
     connect(core, &Core::friendTypingChanged, this, &ChatForm::onFriendTypingChanged);
     connect(core, &Core::friendStatusChanged, this, &ChatForm::onFriendStatusChanged);
-    connect(core, &Core::fileNameChanged, this, &ChatForm::onFileNameChanged);
+    connect(coreFile, &CoreFile::fileNameChanged, this, &ChatForm::onFileNameChanged);
 
 
     const CoreAV* av = core->getAv();
@@ -297,7 +299,7 @@ void ChatForm::onAttachClicked()
         }
 
         qint64 filesize = file.size();
-        core->sendFile(f->getId(), fileName, path, filesize);
+        core->getCoreFile()->sendFile(f->getId(), fileName, path, filesize);
     }
 }
 
@@ -762,7 +764,7 @@ void ChatForm::dropEvent(QDropEvent* ev)
         }
 
         if (info.exists()) {
-            core->sendFile(f->getId(), fileName, info.absoluteFilePath(), info.size());
+            core->getCoreFile()->sendFile(f->getId(), fileName, info.absoluteFilePath(), info.size());
         }
     }
 }
@@ -984,7 +986,8 @@ void ChatForm::sendImage(const QPixmap& pixmap)
         qint64 filesize = file.size();
         file.close();
         QFileInfo fi(file);
-        Core::getInstance()->sendFile(f->getId(), fi.fileName(), fi.filePath(), filesize);
+        CoreFile* coreFile = Core::getInstance()->getCoreFile();
+        coreFile->sendFile(f->getId(), fi.fileName(), fi.filePath(), filesize);
     } else {
         QMessageBox::warning(this,
                              tr("Failed to open temporary file", "Temporary file for screenshot"),
diff --git a/src/widget/widget.cpp b/src/widget/widget.cpp
index 56f3d70a7..68a621c4c 100644
--- a/src/widget/widget.cpp
+++ b/src/widget/widget.cpp
@@ -51,6 +51,7 @@
 #include "src/audio/audio.h"
 #include "src/core/core.h"
 #include "src/core/coreav.h"
+#include "src/core/corefile.h"
 #include "src/model/chatroom/friendchatroom.h"
 #include "src/model/chatroom/groupchatroom.h"
 #include "src/model/friend.h"
@@ -234,6 +235,7 @@ void Widget::init()
 #endif
 
     Core* core = Nexus::getCore();
+    CoreFile* coreFile = core->getCoreFile();
     Profile* profile = Nexus::getProfile();
     profileInfo = new ProfileInfo(core, profile);
     profileForm = new ProfileForm(profileInfo);
@@ -243,8 +245,8 @@ void Widget::init()
 
     connect(profile, &Profile::selfAvatarChanged, profileForm, &ProfileForm::onSelfAvatarLoaded);
 
-    connect(core, &Core::fileDownloadFinished, filesForm, &FilesForm::onFileDownloadComplete);
-    connect(core, &Core::fileUploadFinished, filesForm, &FilesForm::onFileUploadComplete);
+    connect(coreFile, &CoreFile::fileDownloadFinished, filesForm, &FilesForm::onFileDownloadComplete);
+    connect(coreFile, &CoreFile::fileUploadFinished, filesForm, &FilesForm::onFileUploadComplete);
     connect(ui->addButton, &QPushButton::clicked, this, &Widget::onAddClicked);
     connect(ui->groupButton, &QPushButton::clicked, this, &Widget::onGroupClicked);
     connect(ui->transferButton, &QPushButton::clicked, this, &Widget::onTransferClicked);