diff --git a/Scripts/Editor/NodeEditorReflection.cs b/Scripts/Editor/NodeEditorReflection.cs
index 18b72fa..6b8b121 100644
--- a/Scripts/Editor/NodeEditorReflection.cs
+++ b/Scripts/Editor/NodeEditorReflection.cs
@@ -77,18 +77,28 @@ namespace XNodeEditor {
             foreach (Assembly assembly in assemblies) {
                 try {
                     types.AddRange(assembly.GetTypes().Where(t => !t.IsAbstract && baseType.IsAssignableFrom(t)).ToArray());
-                } catch(ReflectionTypeLoadException) {}
+                } catch (ReflectionTypeLoadException) { }
             }
             return types.ToArray();
         }
 
         public static void AddCustomContextMenuItems(GenericMenu contextMenu, object obj) {
-            KeyValuePair<ContextMenu, System.Reflection.MethodInfo>[] items = GetContextMenuMethods(obj);
+            KeyValuePair<ContextMenu, MethodInfo>[] items = GetContextMenuMethods(obj);
             if (items.Length != 0) {
                 contextMenu.AddSeparator("");
+                List<string> invalidatedEntries = new List<string>();
+                foreach (KeyValuePair<ContextMenu, MethodInfo> checkValidate in items) {
+                    if (checkValidate.Key.validate && !(bool) checkValidate.Value.Invoke(obj, null)) {
+                        invalidatedEntries.Add(checkValidate.Key.menuItem);
+                    }
+                }
                 for (int i = 0; i < items.Length; i++) {
-                    KeyValuePair<ContextMenu, System.Reflection.MethodInfo> kvp = items[i];
-                    contextMenu.AddItem(new GUIContent(kvp.Key.menuItem), false, () => kvp.Value.Invoke(obj, null));
+                    KeyValuePair<ContextMenu, MethodInfo> kvp = items[i];
+                    if (invalidatedEntries.Contains(kvp.Key.menuItem)) {
+                        contextMenu.AddDisabledItem(new GUIContent(kvp.Key.menuItem));
+                    } else {
+                        contextMenu.AddItem(new GUIContent(kvp.Key.menuItem), false, () => kvp.Value.Invoke(obj, null));
+                    }
                 }
             }
         }