diff --git a/Foundation/CPKeyValueObserving.j b/Foundation/CPKeyValueObserving.j
index b88f766a0..39f29779d 100644
--- a/Foundation/CPKeyValueObserving.j
+++ b/Foundation/CPKeyValueObserving.j
@@ -480,6 +480,11 @@ var kvoNewAndOld = CPKeyValueObservingOptionNew|CPKeyValueObservingOptionOld,
 
 - (void)willChangeValueForKey:(CPString)aKey
 {
+    var superClass = [self class],
+    methodSelector = @selector(willChangeValueForKey:),
+    methodImp = class_getMethodImplementation(superClass, methodSelector);
+    methodImp(self, methodSelector, aKey);
+    
     if (!aKey)
         return;
 
@@ -490,6 +495,11 @@ var kvoNewAndOld = CPKeyValueObservingOptionNew|CPKeyValueObservingOptionOld,
 
 - (void)didChangeValueForKey:(CPString)aKey
 {
+    var superClass = [self class],
+    methodSelector = @selector(didChangeValueForKey:),
+    methodImp = class_getMethodImplementation(superClass, methodSelector);
+    methodImp(self, methodSelector, aKey);
+    
     if (!aKey)
         return;
 
@@ -498,6 +508,11 @@ var kvoNewAndOld = CPKeyValueObservingOptionNew|CPKeyValueObservingOptionOld,
 
 - (void)willChange:(CPKeyValueChange)change valuesAtIndexes:(CPIndexSet)indexes forKey:(CPString)aKey
 {
+    var superClass = [self class],
+    methodSelector = @selector(willChange:valuesAtIndexes:forKey:),
+    methodImp = class_getMethodImplementation(superClass, methodSelector);
+    methodImp(self, methodSelector, change, indexes, aKey);
+    
     if (!aKey)
         return;
 
@@ -508,6 +523,11 @@ var kvoNewAndOld = CPKeyValueObservingOptionNew|CPKeyValueObservingOptionOld,
 
 - (void)didChange:(CPKeyValueChange)change valuesAtIndexes:(CPIndexSet)indexes forKey:(CPString)aKey
 {
+    var superClass = [self class],
+    methodSelector = @selector(didChange:valuesAtIndexes:forKey:),
+    methodImp = class_getMethodImplementation(superClass, methodSelector);
+    methodImp(self, methodSelector, change, indexes, aKey);
+    
     if (!aKey)
         return;