make: Added AC_CONFIG_MACRO_DIR([m4]).
diff --git a/.gitignore b/.gitignore
index 58ff835..16aef12 100644
--- a/.gitignore
+++ b/.gitignore
@@ -25,6 +25,7 @@
 /ndn-cpp/stamp-h1
 /aclocal.m4
 /libtool
+/m4/*
 *.Po
 .deps
 .dirstamp