diff --git a/dspy/teleprompt/signature_opt.py b/dspy/teleprompt/signature_opt.py
index d71aa69a7d..e760ebf45b 100644
--- a/dspy/teleprompt/signature_opt.py
+++ b/dspy/teleprompt/signature_opt.py
@@ -96,7 +96,7 @@ def _print_signature(self, predictor):
             else:
                 signature = predictor.extended_signature1
             print(f"i: {signature.instructions}")
-            print(f"p: {list(signature.fields().values())[-1].json_schema_extra['prefix']}")
+            print(f"p: {list(signature.fields.values())[-1].json_schema_extra['prefix']}")
             print()