--- a/Makefile.am
+++ b/Makefile.am
@@ -6,7 +6,7 @@ pkgconfig_DATA = ffms2.pc
 
 dist_doc_DATA = doc/ffms2-api.html doc/ffms2-changelog.html doc/style.css
 
-INCLUDES = -I. -I$(top_srcdir)/include -I$(top_srcdir)/src/config @LIBAV_CFLAGS@ @ZLIB_CPPFLAGS@ -include config.h
+AM_CPPFLAGS = -I. -I$(top_srcdir)/include -I$(top_srcdir)/src/config @LIBAV_CFLAGS@ @ZLIB_CPPFLAGS@ -include config.h
 
 lib_LTLIBRARIES = src/core/libffms2.la
 src_core_libffms2_la_LIBADD = @LIBAV_LIBS@ @ZLIB_LDFLAGS@ -lz @LTUNDEF@