diff --git a/src/support/SignalSlot.cpp b/src/support/SignalSlot.cpp
index 27a62d2b83..a6d1297df3 100644
--- a/src/support/SignalSlot.cpp
+++ b/src/support/SignalSlot.cpp
@@ -9,6 +9,8 @@
  * Full author contact details are available in file CREDITS.
  */
 
+#include <config.h>
+
 #include "SignalSlot.h"
 #include "SignalSlotPrivate.h"