diff --git a/gtk/gtkthemingengine.c b/gtk/gtkthemingengine.c
index 89a5f443d2..a430b8c767 100644
--- a/gtk/gtkthemingengine.c
+++ b/gtk/gtkthemingengine.c
@@ -36,6 +36,8 @@
 #include "gtkroundedboxprivate.h"
 #include "gtkthemingbackgroundprivate.h"
 
+#include "fallback-c89.c"
+
 /**
  * SECTION:gtkthemingengine
  * @Short_description: Theming renderers