diff --git a/Makefile.am b/Makefile.am
index e49a2a6..7d4aaa5 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -7,6 +7,8 @@ SUBDIRS = lib comedi_calibrate comedi_config man testing demo doc python \
 
 EXTRA_DIST = debian m4 comedilib.spec 
 
+ACLOCAL_AMFLAGS = -I m4
+
 dist-hook:
 	rm -rf `find $(distdir) -name CVS`