diff --git a/build-constraints.yaml b/build-constraints.yaml
index b5103c15..7c561f66 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -6806,7 +6806,7 @@ packages:
       - texmath < 0.12.4
       - ipynb < 0.2
 
-      # https://github.com/haskell-game/sdl2/issues/240
+      # https://github.com/haskell-game/sdl2/issues/240 (need newer Ubuntu)
       - sdl2 < 2.5.3.1
 
 # end of packages