diff --git a/Makefile.am b/Makefile.am
index 5ad354a..a0a43fc 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,3 +1,5 @@
+ACLOCAL_AMFLAGS = -I autoconf-archive/m4
+
 EXTRA_DIST = README.md README.html
 EXTRA_DIST += config.h.win32
 EXTRA_DIST += Doxyfile