diff --git a/geometry.cpp b/geometry.cpp
index 9070f9f876..ff60cfd8a5 100644
--- a/geometry.cpp
+++ b/geometry.cpp
@@ -3150,7 +3150,8 @@ void Client::performMoveResize()
     if( isElectricBorderMaximizing() )
         return;
 #ifdef HAVE_XSYNC
-    if( isResize() && sync_counter != None && !sync_resize_pending )
+    if( isResize() && options->resizeMode == Options::Opaque &&
+        sync_counter != None && !sync_resize_pending )
         {
         sync_timeout = new QTimer( this );
         connect( sync_timeout, SIGNAL( timeout()), SLOT( syncTimeout()));