diff --git a/lib/linguist/languages.yml b/lib/linguist/languages.yml
index 77da5506..e1b57dc9 100644
--- a/lib/linguist/languages.yml
+++ b/lib/linguist/languages.yml
@@ -2648,6 +2648,7 @@ Sage:
   group: Python
   extensions:
   - .sage
+  - .sagews
   tm_scope: source.python
   ace_mode: python