diff --git a/glib/gthread.h b/glib/gthread.h
index 40dafe511..9f5b34b54 100644
--- a/glib/gthread.h
+++ b/glib/gthread.h
@@ -271,7 +271,7 @@ struct _GStaticRecMutex
   GSystemThread owner;
 };
 
-#define G_STATIC_REC_MUTEX_INIT { G_STATIC_MUTEX_INIT, 0 }
+#define G_STATIC_REC_MUTEX_INIT { G_STATIC_MUTEX_INIT, 0, {{0, 0, 0, 0}} }
 void     g_static_rec_mutex_init        (GStaticRecMutex *mutex);
 void     g_static_rec_mutex_lock        (GStaticRecMutex *mutex);
 gboolean g_static_rec_mutex_trylock     (GStaticRecMutex *mutex);