diff --git a/.gitignore b/.gitignore
index 91e40cd..dde04e4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -26,6 +26,7 @@
 /install-sh
 /missing
 /stamp-h1
+/m4
 
 # https://www.gnu.org/software/libtool/