diff --git a/gtk/tests/Makefile.am b/gtk/tests/Makefile.am
index c7bd43a003..0bbd4f5197 100644
--- a/gtk/tests/Makefile.am
+++ b/gtk/tests/Makefile.am
@@ -6,6 +6,8 @@ AM_CPPFLAGS = \
 	-I$(top_srcdir)			\
 	-I$(top_builddir)/gdk		\
 	-I$(top_srcdir)/gdk		\
+	-I$(top_builddir)/gtk		\
+	-I$(top_srcdir)/gtk		\
 	-DSRCDIR=\""$(abs_srcdir)"\"	\
 	$(GTK_DEBUG_FLAGS)		\
 	$(GTK_DEP_CFLAGS)