diff --git a/Makefile.am b/Makefile.am
index 2638b9f..e622c1d 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,3 +1,4 @@
+ACLOCAL_AMFLAGS = -I m4 ${ACLOCAL_FLAGS}
 SUBDIRS = doc libevdev tools test
 
 pkgconfigdir = $(libdir)/pkgconfig