diff --git a/src/support/SignalSlotPrivate.cpp b/src/support/SignalSlotPrivate.cpp
index 59bd265ee5..ea3217fd6b 100644
--- a/src/support/SignalSlotPrivate.cpp
+++ b/src/support/SignalSlotPrivate.cpp
@@ -9,6 +9,7 @@
  * Full author contact details are available in file CREDITS.
  */
 
+#include <config.h>
 
 // trigger moc 
 #include "SignalSlotPrivate_moc.cpp"