diff --git a/libs/langgraph/langgraph/graph/state.py b/libs/langgraph/langgraph/graph/state.py
index b64e54b21..1eba5f7de 100644
--- a/libs/langgraph/langgraph/graph/state.py
+++ b/libs/langgraph/langgraph/graph/state.py
@@ -342,7 +342,7 @@ class StateGraph(Graph):
 
         ends = EMPTY_SEQ
         try:
-            if isfunction(action) and (
+            if (isfunction(action) or ismethod(getattr(action, "__call__", None))) and (
                 hints := get_type_hints(getattr(action, "__call__"))
                 or get_type_hints(action)
             ):