diff --git a/libs/core/langchain_core/runnables/utils.py b/libs/core/langchain_core/runnables/utils.py
index 992ea077bf..03edb0c291 100644
--- a/libs/core/langchain_core/runnables/utils.py
+++ b/libs/core/langchain_core/runnables/utils.py
@@ -248,7 +248,12 @@ def get_function_nonlocals(func: Callable) -> List[Any]:
                 if "." in kk and kk.startswith(k):
                     vv = v
                     for part in kk.split(".")[1:]:
-                        vv = getattr(vv, part)
+                        if vv is None:
+                            break
+                        else:
+                            vv = getattr(vv, part)
+                    else:
+                        values.append(vv)
                     values.append(vv)
         return values
     except (SyntaxError, TypeError, OSError):