diff --git a/libs/langgraph/langgraph/pregel/__init__.py b/libs/langgraph/langgraph/pregel/__init__.py
index 515a33aa4..cee4e16dc 100644
--- a/libs/langgraph/langgraph/pregel/__init__.py
+++ b/libs/langgraph/langgraph/pregel/__init__.py
@@ -1117,18 +1117,13 @@ class Pregel(
         def output() -> Iterator:
             while loop.stream:
                 ns, mode, payload = loop.stream.popleft()
-                ns = (
-                    NS_SEP.join(p.split(NS_END)[0] for p in ns.split(NS_SEP))
-                    if ns
-                    else ""
-                )
                 if mode in stream_modes:
                     if subgraphs and isinstance(stream_mode, list):
-                        yield (ns, mode, payload)
+                        yield (tuple(ns.split(NS_SEP)) if ns else (), mode, payload)
                     elif isinstance(stream_mode, list):
                         yield (mode, payload)
                     elif subgraphs:
-                        yield (ns, payload)
+                        yield (tuple(ns.split(NS_SEP)) if ns else (), payload)
                     else:
                         yield payload
 
@@ -1364,18 +1359,13 @@ class Pregel(
         def output() -> Iterator:
             while loop.stream:
                 ns, mode, payload = loop.stream.popleft()
-                ns = (
-                    NS_SEP.join(p.split(NS_END)[0] for p in ns.split(NS_SEP))
-                    if ns
-                    else ""
-                )
                 if mode in stream_modes:
                     if subgraphs and isinstance(stream_mode, list):
-                        yield (ns, mode, payload)
+                        yield (tuple(ns.split(NS_SEP)) if ns else (), mode, payload)
                     elif isinstance(stream_mode, list):
                         yield (mode, payload)
                     elif subgraphs:
-                        yield (ns, payload)
+                        yield (tuple(ns.split(NS_SEP)) if ns else (), payload)
                     else:
                         yield payload
 
diff --git a/libs/langgraph/tests/test_pregel.py b/libs/langgraph/tests/test_pregel.py
index a6a338a75..269e2bbcc 100644
--- a/libs/langgraph/tests/test_pregel.py
+++ b/libs/langgraph/tests/test_pregel.py
@@ -10898,8 +10898,11 @@ def test_doubly_nested_graph_state(
     # test invoke w/ nested interrupt
     config = {"configurable": {"thread_id": "1"}}
     assert [c for c in app.stream({"my_key": "my value"}, config, subgraphs=True)] == [
-        ("", {"parent_1": {"my_key": "hi my value"}}),
-        ("child|child_1", {"grandchild_1": {"my_key": "hi my value here"}}),
+        ((), {"parent_1": {"my_key": "hi my value"}}),
+        (
+            (AnyStr("child:"), AnyStr("child_1:")),
+            {"grandchild_1": {"my_key": "hi my value here"}},
+        ),
     ]
     # get state without subgraphs
     outer_state = app.get_state(config)
@@ -11121,10 +11124,13 @@ def test_doubly_nested_graph_state(
     )
     # resume
     assert [c for c in app.stream(None, config, subgraphs=True)] == [
-        ("child|child_1", {"grandchild_2": {"my_key": "hi my value here and there"}}),
-        ("child", {"child_1": {"my_key": "hi my value here and there"}}),
-        ("", {"child": {"my_key": "hi my value here and there"}}),
-        ("", {"parent_2": {"my_key": "hi my value here and there and back again"}}),
+        (
+            (AnyStr("child:"), AnyStr("child_1:")),
+            {"grandchild_2": {"my_key": "hi my value here and there"}},
+        ),
+        ((AnyStr("child:"),), {"child_1": {"my_key": "hi my value here and there"}}),
+        ((), {"child": {"my_key": "hi my value here and there"}}),
+        ((), {"parent_2": {"my_key": "hi my value here and there and back again"}}),
     ]
     # get state with and without subgraphs
     assert (
diff --git a/libs/langgraph/tests/test_pregel_async.py b/libs/langgraph/tests/test_pregel_async.py
index 830d69238..b24848e6d 100644
--- a/libs/langgraph/tests/test_pregel_async.py
+++ b/libs/langgraph/tests/test_pregel_async.py
@@ -9341,8 +9341,11 @@ async def test_doubly_nested_graph_state(
     assert [
         c async for c in app.astream({"my_key": "my value"}, config, subgraphs=True)
     ] == [
-        ("", {"parent_1": {"my_key": "hi my value"}}),
-        ("child|child_1", {"grandchild_1": {"my_key": "hi my value here"}}),
+        ((), {"parent_1": {"my_key": "hi my value"}}),
+        (
+            (AnyStr("child:"), AnyStr("child_1:")),
+            {"grandchild_1": {"my_key": "hi my value here"}},
+        ),
     ]
     # get state without subgraphs
     outer_state = await app.aget_state(config)
@@ -9564,10 +9567,13 @@ async def test_doubly_nested_graph_state(
     )
     # resume
     assert [c async for c in app.astream(None, config, subgraphs=True)] == [
-        ("child|child_1", {"grandchild_2": {"my_key": "hi my value here and there"}}),
-        ("child", {"child_1": {"my_key": "hi my value here and there"}}),
-        ("", {"child": {"my_key": "hi my value here and there"}}),
-        ("", {"parent_2": {"my_key": "hi my value here and there and back again"}}),
+        (
+            (AnyStr("child:"), AnyStr("child_1:")),
+            {"grandchild_2": {"my_key": "hi my value here and there"}},
+        ),
+        ((AnyStr("child:"),), {"child_1": {"my_key": "hi my value here and there"}}),
+        ((), {"child": {"my_key": "hi my value here and there"}}),
+        ((), {"parent_2": {"my_key": "hi my value here and there and back again"}}),
     ]
     # get state with and without subgraphs
     assert (