diff --git a/kitty/key_encoding.c b/kitty/key_encoding.c
index 04f18435c..df31f8923 100644
--- a/kitty/key_encoding.c
+++ b/kitty/key_encoding.c
@@ -43,6 +43,7 @@ is_modifier_key(uint32_t key) {
         default:
             return false;
     }
+    END_ALLOW_CASE_RANGE
 }
 
 static inline void