diff --git a/auto_tests/onion_test.c b/auto_tests/onion_test.c
index bd29dcf8..501114a5 100644
--- a/auto_tests/onion_test.c
+++ b/auto_tests/onion_test.c
@@ -48,12 +48,12 @@ static int handle_test_1(void *object, IP_Port source, const uint8_t *packet, ui
 {
     Onion *onion = (Onion *)object;
 
-    if (memcmp(packet, "Install Gentoo", sizeof("Install Gentoo")) != 0) {
+    if (memcmp(packet, "\x83 Install Gentoo", sizeof("\x83 Install Gentoo")) != 0) {
         return 1;
     }
 
-    if (send_onion_response(onion->net, source, (const uint8_t *)"install gentoo", sizeof("install gentoo"),
-                            packet + sizeof("Install Gentoo")) == -1) {
+    if (send_onion_response(onion->net, source, (const uint8_t *)"\x84 install gentoo", sizeof("\x84 install gentoo"),
+                            packet + sizeof("\x84 install gentoo")) == -1) {
         return 1;
     }
 
@@ -64,11 +64,11 @@ static int handle_test_1(void *object, IP_Port source, const uint8_t *packet, ui
 static int handled_test_2;
 static int handle_test_2(void *object, IP_Port source, const uint8_t *packet, uint16_t length, void *userdata)
 {
-    if (length != sizeof("install Gentoo")) {
+    if (length != sizeof("\x84 install gentoo")) {
         return 1;
     }
 
-    if (memcmp(packet, (const uint8_t *)"install gentoo", sizeof("install gentoo")) != 0) {
+    if (memcmp(packet, (const uint8_t *)"\x84 install gentoo", sizeof("\x84 install gentoo")) != 0) {
         return 1;
     }
 
@@ -170,7 +170,7 @@ START_TEST(test_basic)
     Onion *onion1 = new_onion(new_DHT(log1, new_networking(log1, ip, 34567), true));
     Onion *onion2 = new_onion(new_DHT(log2, new_networking(log2, ip, 34568), true));
     ck_assert_msg((onion1 != nullptr) && (onion2 != nullptr), "Onion failed initializing.");
-    networking_registerhandler(onion2->net, 'I', &handle_test_1, onion2);
+    networking_registerhandler(onion2->net, NET_PACKET_ANNOUNCE_REQUEST, &handle_test_1, onion2);
 
     IP_Port on1 = {ip, net_port(onion1->net)};
     Node_format n1;
@@ -189,8 +189,8 @@ START_TEST(test_basic)
     nodes[3] = n2;
     Onion_Path path;
     create_onion_path(onion1->dht, &path, nodes);
-    int ret = send_onion_packet(onion1->net, &path, nodes[3].ip_port, (const uint8_t *)"Install Gentoo",
-                                sizeof("Install Gentoo"));
+    int ret = send_onion_packet(onion1->net, &path, nodes[3].ip_port, (const uint8_t *)"\x83 Install Gentoo",
+                                sizeof("\x83 Install Gentoo"));
     ck_assert_msg(ret == 0, "Failed to create/send onion packet.");
 
     handled_test_1 = 0;
@@ -200,7 +200,7 @@ START_TEST(test_basic)
         do_onion(onion2);
     }
 
-    networking_registerhandler(onion1->net, 'i', &handle_test_2, onion1);
+    networking_registerhandler(onion1->net, NET_PACKET_ANNOUNCE_RESPONSE, &handle_test_2, onion1);
     handled_test_2 = 0;
 
     while (handled_test_2 == 0) {
diff --git a/toxcore/onion.c b/toxcore/onion.c
index 48cc4d76..740c25ce 100644
--- a/toxcore/onion.c
+++ b/toxcore/onion.c
@@ -471,6 +471,15 @@ static int handle_send_2(void *object, IP_Port source, const uint8_t *packet, ui
         return 1;
     }
 
+    if (len <= SIZE_IPPORT) {
+        return 1;
+    }
+
+    if (plain[SIZE_IPPORT] != NET_PACKET_ANNOUNCE_REQUEST &&
+            plain[SIZE_IPPORT] != NET_PACKET_ONION_DATA_REQUEST) {
+        return 1;
+    }
+
     IP_Port send_to;
 
     if (ipport_unpack(&send_to, plain, len, 0) == -1) {
@@ -514,6 +523,11 @@ static int handle_recv_3(void *object, IP_Port source, const uint8_t *packet, ui
         return 1;
     }
 
+    if (packet[1 + RETURN_3] != NET_PACKET_ANNOUNCE_RESPONSE &&
+            packet[1 + RETURN_3] != NET_PACKET_ONION_DATA_RESPONSE) {
+        return 1;
+    }
+
     change_symmetric_key(onion);
 
     uint8_t plain[SIZE_IPPORT + RETURN_2];
@@ -555,6 +569,11 @@ static int handle_recv_2(void *object, IP_Port source, const uint8_t *packet, ui
         return 1;
     }
 
+    if (packet[1 + RETURN_2] != NET_PACKET_ANNOUNCE_RESPONSE &&
+            packet[1 + RETURN_2] != NET_PACKET_ONION_DATA_RESPONSE) {
+        return 1;
+    }
+
     change_symmetric_key(onion);
 
     uint8_t plain[SIZE_IPPORT + RETURN_1];
@@ -596,6 +615,11 @@ static int handle_recv_1(void *object, IP_Port source, const uint8_t *packet, ui
         return 1;
     }
 
+    if (packet[1 + RETURN_1] != NET_PACKET_ANNOUNCE_RESPONSE &&
+            packet[1 + RETURN_1] != NET_PACKET_ONION_DATA_RESPONSE) {
+        return 1;
+    }
+
     change_symmetric_key(onion);
 
     uint8_t plain[SIZE_IPPORT];