diff --git a/other/apidsl/tox.in.h b/other/apidsl/tox.in.h
index b1b68117..4c9c4972 100644
--- a/other/apidsl/tox.in.h
+++ b/other/apidsl/tox.in.h
@@ -1435,7 +1435,7 @@ namespace friend {
    * This event is triggered when the friend receives the message sent with
    * ${send.message} with the corresponding message ID.
    */
-  event read_receipt {
+  event read_receipt const {
     /**
      * @param friend_number The friend number of the friend who received the message.
      * @param message_id The message ID as returned from ${send.message}
diff --git a/toxcore/Messenger.c b/toxcore/Messenger.c
index ac54f34f..b87e61c6 100644
--- a/toxcore/Messenger.c
+++ b/toxcore/Messenger.c
@@ -344,7 +344,7 @@ static int friend_received_packet(const Messenger *m, int32_t friendnumber, uint
                                 m->friendlist[friendnumber].friendcon_id), number);
 }
 
-static int do_receipts(Messenger *m, int32_t friendnumber)
+static int do_receipts(Messenger *m, int32_t friendnumber, void *userdata)
 {
     if (friend_not_valid(m, friendnumber))
         return -1;
@@ -357,8 +357,9 @@ static int do_receipts(Messenger *m, int32_t friendnumber)
         if (friend_received_packet(m, friendnumber, receipts->packet_num) == -1)
             break;
 
-        if (m->read_receipt)
-            (*m->read_receipt)(m, friendnumber, receipts->msg_id, m->read_receipt_userdata);
+        if (m->read_receipt) {
+            (*m->read_receipt)(m, friendnumber, receipts->msg_id, userdata);
+        }
 
         free(receipts);
         m->friendlist[friendnumber].receipts_start = temp_r;
@@ -796,10 +797,9 @@ void m_callback_typingchange(Messenger *m, void(*function)(Messenger *m, uint32_
     m->friend_typingchange = function;
 }
 
-void m_callback_read_receipt(Messenger *m, void (*function)(Messenger *m, uint32_t, uint32_t, void *), void *userdata)
+void m_callback_read_receipt(Messenger *m, void (*function)(Messenger *m, uint32_t, uint32_t, void *))
 {
     m->read_receipt = function;
-    m->read_receipt_userdata = userdata;
 }
 
 void m_callback_connectionstatus(Messenger *m, void (*function)(Messenger *m, uint32_t, unsigned int, void *),
@@ -2168,7 +2168,7 @@ static int handle_packet(void *object, int i, uint8_t *temp, uint16_t len, void
     return 0;
 }
 
-void do_friends(Messenger *m)
+static void do_friends(Messenger *m, void *userdata)
 {
     uint32_t i;
     uint64_t temp_time = unix_time();
@@ -2217,7 +2217,7 @@ void do_friends(Messenger *m)
             }
 
             check_friend_tcp_udp(m, i);
-            do_receipts(m, i);
+            do_receipts(m, i, userdata);
             do_reqchunk_filecb(m, i);
 
             m->friendlist[i].last_seen_time = (uint64_t) time(NULL);
@@ -2311,7 +2311,7 @@ void do_messenger(Messenger *m, void *userdata)
     do_net_crypto(m->net_crypto, userdata);
     do_onion_client(m->onion_c);
     do_friend_connections(m->fr_c);
-    do_friends(m);
+    do_friends(m, userdata);
     connection_status_cb(m, userdata);
 
 #ifdef TOX_LOGGER
diff --git a/toxcore/Messenger.h b/toxcore/Messenger.h
index 0141f1ea..6ac06f2f 100644
--- a/toxcore/Messenger.h
+++ b/toxcore/Messenger.h
@@ -242,7 +242,6 @@ struct Messenger {
     void (*friend_userstatuschange)(struct Messenger *m, uint32_t, unsigned int, void *);
     void (*friend_typingchange)(struct Messenger *m, uint32_t, _Bool, void *);
     void (*read_receipt)(struct Messenger *m, uint32_t, uint32_t, void *);
-    void *read_receipt_userdata;
     void (*friend_connectionstatuschange)(struct Messenger *m, uint32_t, unsigned int, void *);
     void *friend_connectionstatuschange_userdata;
     void (*friend_connectionstatuschange_internal)(struct Messenger *m, uint32_t, uint8_t, void *);
@@ -507,7 +506,7 @@ void m_callback_typingchange(Messenger *m, void(*function)(Messenger *m, uint32_
  *  Since core doesn't track ids for you, receipt may not correspond to any message.
  *  In that case, you should discard it.
  */
-void m_callback_read_receipt(Messenger *m, void (*function)(Messenger *m, uint32_t, uint32_t, void *), void *userdata);
+void m_callback_read_receipt(Messenger *m, void (*function)(Messenger *m, uint32_t, uint32_t, void *));
 
 /* Set the callback for connection status changes.
  *  function(uint32_t friendnumber, uint8_t status)
diff --git a/toxcore/tox.c b/toxcore/tox.c
index 2cccf125..b1308d90 100644
--- a/toxcore/tox.c
+++ b/toxcore/tox.c
@@ -890,10 +890,10 @@ uint32_t tox_friend_send_message(Tox *tox, uint32_t friend_number, TOX_MESSAGE_T
     return message_id;
 }
 
-void tox_callback_friend_read_receipt(Tox *tox, tox_friend_read_receipt_cb *function, void *user_data)
+void tox_callback_friend_read_receipt(Tox *tox, tox_friend_read_receipt_cb *function)
 {
     Messenger *m = tox;
-    m_callback_read_receipt(m, function, user_data);
+    m_callback_read_receipt(m, function);
 }
 
 void tox_callback_friend_request(Tox *tox, tox_friend_request_cb *function, void *user_data)
diff --git a/toxcore/tox.h b/toxcore/tox.h
index e392ecff..16e83207 100644
--- a/toxcore/tox.h
+++ b/toxcore/tox.h
@@ -1531,7 +1531,7 @@ typedef void tox_friend_read_receipt_cb(Tox *tox, uint32_t friend_number, uint32
  * This event is triggered when the friend receives the message sent with
  * tox_friend_send_message with the corresponding message ID.
  */
-void tox_callback_friend_read_receipt(Tox *tox, tox_friend_read_receipt_cb *callback, void *user_data);
+void tox_callback_friend_read_receipt(Tox *tox, tox_friend_read_receipt_cb *callback);
 
 
 /*******************************************************************************