diff --git a/comfy_api/internal/__init__.py b/comfy_api/internal/__init__.py
index 939d09b8d..7321b7845 100644
--- a/comfy_api/internal/__init__.py
+++ b/comfy_api/internal/__init__.py
@@ -36,6 +36,13 @@ class _ComfyNodeInternal:
         ...
 
 
+class _NodeOutputInternal:
+    """Class that all V3-based APIs inherit from for NodeOutput.
+
+    This is intended to only be referenced within execution.py, as it has to handle all V3 APIs going forward."""
+    ...
+
+
 def as_pruned_dict(dataclass_obj):
     '''Return dict of dataclass object with pruned None values.'''
     return prune_dict(asdict(dataclass_obj))
diff --git a/comfy_api/v3/_io.py b/comfy_api/v3/_io.py
index 3ead59733..88a88f867 100644
--- a/comfy_api/v3/_io.py
+++ b/comfy_api/v3/_io.py
@@ -22,7 +22,7 @@ from comfy.samplers import CFGGuider, Sampler
 from comfy.sd import CLIP, VAE
 from comfy.sd import StyleModel as StyleModel_
 from comfy_api.input import VideoInput
-from comfy_api.internal import (_ComfyNodeInternal, classproperty, copy_class, first_real_override, is_class,
+from comfy_api.internal import (_ComfyNodeInternal, _NodeOutputInternal, classproperty, copy_class, first_real_override, is_class,
     prune_dict, shallow_clone_class)
 from comfy_api.v3._resources import Resources, ResourcesLocal
 from comfy_execution.graph import ExecutionBlocker
@@ -1486,7 +1486,7 @@ class ComfyNode(_ComfyNodeBaseInternal):
         return ComfyNode
 
 
-class NodeOutput:
+class NodeOutput(_NodeOutputInternal):
     '''
     Standardized output of a node; can pass in any number of args and/or a UIOutput into 'ui' kwarg.
     '''
diff --git a/execution.py b/execution.py
index 608006467..3bea0f048 100644
--- a/execution.py
+++ b/execution.py
@@ -32,7 +32,7 @@ from comfy_execution.graph_utils import GraphBuilder, is_link
 from comfy_execution.validation import validate_node_input
 from comfy_execution.progress import get_progress_state, reset_progress_state, add_progress_handler, WebUIProgressHandler
 from comfy_execution.utils import CurrentNodeContext
-from comfy_api.internal import _ComfyNodeInternal, first_real_override, is_class, make_locked_method_func
+from comfy_api.internal import _ComfyNodeInternal, _NodeOutputInternal, first_real_override, is_class, make_locked_method_func
 from comfy_api.v3 import io, resources
 
 
@@ -358,7 +358,7 @@ def get_output_from_returns(return_values, obj):
                     result = tuple([result] * len(obj.RETURN_TYPES))
                 results.append(result)
                 subgraph_results.append((None, result))
-        elif isinstance(r, io.NodeOutput):
+        elif isinstance(r, _NodeOutputInternal):
             # V3
             if r.ui is not None:
                 if isinstance(r.ui, dict):