diff --git a/lib/linguist/languages.yml b/lib/linguist/languages.yml
index 2e2f5fce..3e015b2b 100644
--- a/lib/linguist/languages.yml
+++ b/lib/linguist/languages.yml
@@ -2031,6 +2031,8 @@ Makefile:
   - Makefile
   - Makefile.inc
   - makefile
+  - Makefile.am
+  - Makefile.in
   interpreters:
   - make
   ace_mode: makefile