diff --git a/toxcore/Lossless_UDP.c b/toxcore/Lossless_UDP.c
index ca8ba8e0..01f9ccc2 100644
--- a/toxcore/Lossless_UDP.c
+++ b/toxcore/Lossless_UDP.c
@@ -480,19 +480,19 @@ uint32_t recvqueue(Lossless_UDP *ludp, int connection_id)
 }
 
 /*  return the id of the next packet in the queue.
- *  return -1 if no packet in queue.
+ *  return ~0 if no packet in queue.
  */
-char id_packet(Lossless_UDP *ludp, int connection_id)
+uint8_t id_packet(Lossless_UDP *ludp, int connection_id)
 {
     if (recvqueue(ludp, connection_id) == 0)
-        return -1;
+        return ~0;
 
     Connection *connection = &tox_array_get(&ludp->connections, connection_id, Connection);
 
     if (connection->status != LUDP_NO_CONNECTION)
         return connection->recvbuffer[connection->successful_read % connection->recvbuffer_length].data[0];
 
-    return -1;
+    return ~0;
 }
 
 /*  return 0 if there is no received data in the buffer.
diff --git a/toxcore/Lossless_UDP.h b/toxcore/Lossless_UDP.h
index d4d6ec4e..b23d602a 100644
--- a/toxcore/Lossless_UDP.h
+++ b/toxcore/Lossless_UDP.h
@@ -198,7 +198,7 @@ IP_Port connection_ip(Lossless_UDP *ludp, int connection_id);
 /*  returns the id of the next packet in the queue.
  *  return -1 if no packet in queue.
  */
-char id_packet(Lossless_UDP *ludp, int connection_id);
+uint8_t id_packet(Lossless_UDP *ludp, int connection_id);
 
 /*  return 0 if there is no received data in the buffer.
  *  return length of received packet if successful.
diff --git a/toxcore/net_crypto.c b/toxcore/net_crypto.c
index 6b64c1b6..9b0f0443 100644
--- a/toxcore/net_crypto.c
+++ b/toxcore/net_crypto.c
@@ -753,7 +753,7 @@ static void receive_crypto(Net_Crypto *c)
                     c->crypto_connections[i].status = CRYPTO_CONN_TIMED_OUT;
                 }
             } else if (id_packet(c->lossless_udp,
-                                 c->crypto_connections[i].number) != -1) {
+                                 c->crypto_connections[i].number) != (uint8_t)~0) {
                 /* This should not happen, timeout the connection if it does. */
                 c->crypto_connections[i].status = CRYPTO_CONN_TIMED_OUT;
             }
@@ -782,7 +782,7 @@ static void receive_crypto(Net_Crypto *c)
                     /* This should not happen, timeout the connection if it does. */
                     c->crypto_connections[i].status = CRYPTO_CONN_TIMED_OUT;
                 }
-            } else if (id_packet(c->lossless_udp, c->crypto_connections[i].number) != -1) {
+            } else if (id_packet(c->lossless_udp, c->crypto_connections[i].number) != (uint8_t)~0) {
                 /* This should not happen, timeout the connection if it does. */
                 c->crypto_connections[i].status = CRYPTO_CONN_TIMED_OUT;
             }