diff --git a/lib/linguist/languages.yml b/lib/linguist/languages.yml
index 3854ed9a..2bf8190f 100644
--- a/lib/linguist/languages.yml
+++ b/lib/linguist/languages.yml
@@ -249,6 +249,7 @@ Common Lisp:
   extensions:
   - .lsp
   - .ny
+  - .asd
 
 Coq:
   type: programming