diff --git a/linphone-app/src/app/single-application/singleapplication_p.cpp b/linphone-app/src/app/single-application/singleapplication_p.cpp
index b13ba5812..4b83c7714 100644
--- a/linphone-app/src/app/single-application/singleapplication_p.cpp
+++ b/linphone-app/src/app/single-application/singleapplication_p.cpp
@@ -316,7 +316,7 @@ bool SingleApplicationPrivate::writeConfirmedFrame( int msecs, const QByteArray
     socket->write( msg );
     socket->flush();
 
-    bool result = socket->waitForReadyRead( msecs ); // await ack byte
+    bool result = socket->waitForReadyRead( msecs < 0 ? -1 : msecs ); // await ack byte
     if (result) {
         socket->read( 1 );
         return true;