diff --git a/Plugins/UEWingman/Source/UEWingman/Handlers/EventDispatcher_Delete.h b/Plugins/UEWingman/Source/UEWingman/Handlers/EventDispatcher_Delete.h
index 94a726f8..042a1c9c 100644
--- a/Plugins/UEWingman/Source/UEWingman/Handlers/EventDispatcher_Delete.h
+++ b/Plugins/UEWingman/Source/UEWingman/Handlers/EventDispatcher_Delete.h
@@ -45,9 +45,6 @@ public:
 		UEdGraph* Graph = *SigGraph;
 		FName VarFName = Var->VarName;
 
-		BP->Modify();
-		Graph->Modify();
-
 		// Remove the member variable (also destroys referencing nodes)
 		FBlueprintEditorUtils::RemoveMemberVariable(BP, VarFName);
 
diff --git a/Plugins/UEWingman/Source/UEWingman/Handlers/GraphNode_SetDefaults.h b/Plugins/UEWingman/Source/UEWingman/Handlers/GraphNode_SetDefaults.h
index 8185d9fe..a85286c9 100644
--- a/Plugins/UEWingman/Source/UEWingman/Handlers/GraphNode_SetDefaults.h
+++ b/Plugins/UEWingman/Source/UEWingman/Handlers/GraphNode_SetDefaults.h
@@ -68,8 +68,6 @@ public:
 			return;
 		}
 
-		Pin->Modify();
-
 		FString UseDefaultValue;
 		TObjectPtr<UObject> UseDefaultObject = nullptr;
 		FText UseDefaultText;
diff --git a/Plugins/UEWingman/Source/UEWingman/Private/WingServer.cpp b/Plugins/UEWingman/Source/UEWingman/Private/WingServer.cpp
index 347880e6..cd066873 100644
--- a/Plugins/UEWingman/Source/UEWingman/Private/WingServer.cpp
+++ b/Plugins/UEWingman/Source/UEWingman/Private/WingServer.cpp
@@ -323,6 +323,9 @@ void UWingServer::TryCallHandler(const FString &Line)
 		return;
 	}
 
+	// MCP handlers must not run inside an undo transaction.
+	check(GUndo == nullptr);
+
 	// Invoke the handler.
 	Handler->Handle();
 }