diff --git a/ldm/invoke/prompt_parser.py b/ldm/invoke/prompt_parser.py
index 7729be78b3..81c4a15235 100644
--- a/ldm/invoke/prompt_parser.py
+++ b/ldm/invoke/prompt_parser.py
@@ -289,7 +289,7 @@ class PromptParser():
 
         return self.flatten(root[0])
 
-    def parse_legacy_blend(self, text: str, skip_normalize: bool) -> Optional[Blend]:
+    def parse_legacy_blend(self, text: str, skip_normalize: bool = False) -> Optional[Blend]:
         weighted_subprompts = split_weighted_subprompts(text, skip_normalize=skip_normalize)
         if len(weighted_subprompts) <= 1:
             return None