--- tests/Makefile.am.orig
+++ tests/Makefile.am
@@ -60,7 +60,8 @@
 	${top_builddir}/lib/sfparse/.libs/*.o
 main_LDFLAGS = -static
 
-AM_CFLAGS = $(WARNCFLAGS) \
+AM_CFLAGS = $(WARNCFLAGS)
+AM_CPPFLAGS = \
 	-I${top_srcdir}/lib \
 	-I${top_srcdir}/lib/includes \
 	-I${top_srcdir}/tests/munit \