diff --git a/.gitignore b/.gitignore
index 1ffc5bc9..3b1d4b23 100644
--- a/.gitignore
+++ b/.gitignore
@@ -17,9 +17,11 @@ install-sh
 libcoap-*.tar.bz2
 libtool
 ltmain.sh
-m4/
-# warn about specific macros in the m4 directory if they missing
-!m4/ax_*
+m4/libtool.m4
+m4/ltoptions.m4
+m4/ltsugar.m4
+m4/ltversion.m4
+m4/lt~obsolete.m4
 missing
 stamp-h1