diff --git a/cogl/Makefile.am b/cogl/Makefile.am
index 2e75cb261..3435fafc7 100644
--- a/cogl/Makefile.am
+++ b/cogl/Makefile.am
@@ -39,6 +39,7 @@ AM_CPPFLAGS = \
 	-DG_DISABLE_DEPRECATED			\
 	-DG_LOG_DOMAIN=\"Cogl-$(COGL_WINSYS)\" 	\
 	-DCLUTTER_COMPILATION			\
+	-DCOGL_ENABLE_EXPERIMENTAL_API		\
 	$(COGL_DEBUG_CFLAGS) 			\
 	$(CLUTTER_DEBUG_CFLAGS) 		\
 	$(NULL)