diff --git a/test/pdiff/Makefile.am b/test/pdiff/Makefile.am
index b900463dd..cc793284f 100644
--- a/test/pdiff/Makefile.am
+++ b/test/pdiff/Makefile.am
@@ -13,7 +13,7 @@ perceptualdiff_SOURCES =	\
 	args.h			\
 	perceptualdiff.c
 
-AC_CPPFLAGS = -I$(top_srcdir)/src -I$(top_builddir)/src $(CAIRO_CFLAGS)
+AM_CPPFLAGS = -I$(top_srcdir)/src -I$(top_builddir)/src $(CAIRO_CFLAGS)
 LDADD = libpdiff.la $(top_builddir)/src/libcairo.la
 #
 # Delete intermediate files as well
diff --git a/test/pdiff/pdiff.h b/test/pdiff/pdiff.h
index b398cc6fe..4a80140c0 100644
--- a/test/pdiff/pdiff.h
+++ b/test/pdiff/pdiff.h
@@ -17,7 +17,7 @@
 #ifndef _PDIFF_H
 #define _PDIFF_H
 
-#include <cairo.h>
+#include "cairo.h"
 
 typedef int bool;
 #ifndef true