diff --git a/Autotools.gitignore b/Autotools.gitignore
index e3923f9..ffa6ecc 100644
--- a/Autotools.gitignore
+++ b/Autotools.gitignore
@@ -1,33 +1,42 @@
 # http://www.gnu.org/software/automake
 
 Makefile.in
 /ar-lib
 /mdate-sh
 /py-compile
 /test-driver
 /ylwrap
 
 # http://www.gnu.org/software/autoconf
 
 /autom4te.cache
 /autoscan.log
 /autoscan-*.log
 /aclocal.m4
 /compile
 /config.guess
 /config.h.in
 /config.sub
 /configure
 /configure.scan
 /depcomp
 /install-sh
 /missing
 /stamp-h1
 
 # https://www.gnu.org/software/libtool/
 
 /ltmain.sh
 
 # http://www.gnu.org/software/texinfo
 
 /texinfo.tex
+
+# http://www.gnu.org/software/m4/
+
+m4/libtool.m4
+m4/ltoptions.m4
+m4/ltsugar.m4
+m4/ltversion.m4
+m4/lt~obsolete.m4
+autom4te.cache