diff --git a/lib/linguist/languages.yml b/lib/linguist/languages.yml
index efa1dfb1..01065eb2 100644
--- a/lib/linguist/languages.yml
+++ b/lib/linguist/languages.yml
@@ -1922,8 +1922,6 @@ M4:
   type: programming
   extensions:
   - .m4
-  filenames:
-  - configure.ac
   tm_scope: none
   ace_mode: text