diff --git a/Makefile.am b/Makefile.am
index 4a83dc7..e755766 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,3 +1,4 @@
+ACLOCAL_AMFLAGS = -I m4
 SUBDIRS = src data po
 
 MAINTAINERCLEANFILES = Makefile.in aclocal.m4 config.guess \