diff --git a/Makefile.am b/Makefile.am
index 383be5d0..ceee75d4 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,2 +1,3 @@
+ACLOCAL_AMFLAGS = -I m4
 SUBDIRS = src examples man
 EXTRA_DIST = COPYING autogen.sh