diff --git a/lib/linguist/languages.yml b/lib/linguist/languages.yml
index 4d36d8d0..44ce9e64 100644
--- a/lib/linguist/languages.yml
+++ b/lib/linguist/languages.yml
@@ -817,6 +817,7 @@ GAMS:
 
 GAP:
   type: programming
+  lexer: GAP
   extensions:
   - .g
   - .gap