diff --git a/gthread/gthread-impl.c b/gthread/gthread-impl.c
index fd03b1d68..6ccf0f656 100644
--- a/gthread/gthread-impl.c
+++ b/gthread/gthread-impl.c
@@ -31,6 +31,8 @@
  * MT safe
  */
 
+#include "config.h"
+
 #include <glib.h>
 
 void