diff --git a/lcl/interfaces/gtk/gtkobject.inc b/lcl/interfaces/gtk/gtkobject.inc
index 1264f6a688..cdbb462ee5 100644
--- a/lcl/interfaces/gtk/gtkobject.inc
+++ b/lcl/interfaces/gtk/gtkobject.inc
@@ -239,7 +239,9 @@ begin
 
 {$ifdef Unix}
   InitSynchronizeSupport;
+{$ifdef UseAsyncProcess}  
   InstallSignalHandler;
+{$endif}
 {$endif}
 
   GTKWidgetSet := Self;