diff --git a/test/Makefile.am b/test/Makefile.am
index eeffbc5..ef6ca11 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -37,6 +37,7 @@ libglx_common_la_SOURCES = \
 
 AM_CPPFLAGS = \
 	-I$(top_srcdir)/include \
+	-I$(top_builddir)/include \
 	$(X11_CFLAGS)
 
 TESTS = \