diff --git a/changelog.md b/changelog.md
index 1b69c89..5e2cc8e 100644
--- a/changelog.md
+++ b/changelog.md
@@ -6,7 +6,7 @@ up to 9a3c7d19609ca8c426a54b252b8509faf63b0bd5
 
 ## Added highlighting of:
 
-- suffix aliases:
+- suffix aliases (requires zsh 5.1.1 or newer):
 
         alias -s png=display
         foo.png