diff --git a/Makefile.am b/Makefile.am
index 38f16683..6f1b6866 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,4 +1,5 @@
 AUTOMAKE_OPTIONS = subdir-objects
+ACLOCAL_AMFLAGS = -I m4
 
 PREFIX=@prefix@
 BINDIR=@bindir@