diff --git a/lcl/interfaces/gtk2/gtk2proc.pp b/lcl/interfaces/gtk2/gtk2proc.pp
index 38c351384c..26919d85bd 100644
--- a/lcl/interfaces/gtk2/gtk2proc.pp
+++ b/lcl/interfaces/gtk2/gtk2proc.pp
@@ -892,7 +892,7 @@ begin
     {$ELSE}
     AWindowManager := 'Nil';
     {$ENDIF}
-    if (AWindowManager = 'fly-wm') or (AWindowManager = 'openbox') then
+    if (AWindowManager = 'fly-wm') or (AWindowManager = 'openbox') or (AWindowManager = 'xfwm4') then
       fLockTopLevelWindowResizeOnNativeCall := 1
     else
       fLockTopLevelWindowResizeOnNativeCall := 0;