diff --git a/AFNetworking/AFURLConnectionOperation.m b/AFNetworking/AFURLConnectionOperation.m
index 675476b..e6cd729 100644
--- a/AFNetworking/AFURLConnectionOperation.m
+++ b/AFNetworking/AFURLConnectionOperation.m
@@ -331,17 +331,19 @@ static inline BOOL AFStateTransitionIsValid(AFOperationState fromState, AFOperat
         _state = state;
         [self didChangeValueForKey:oldStateKey];
         [self didChangeValueForKey:newStateKey];
-        		
-        switch (state) {
-            case AFOperationExecutingState:
-                [[NSNotificationCenter defaultCenter] postNotificationName:AFNetworkingOperationDidStartNotification object:self];
-                break;
-            case AFOperationFinishedState:
-                [[NSNotificationCenter defaultCenter] postNotificationName:AFNetworkingOperationDidFinishNotification object:self];
-                break;
-            default:
-                break;
-        }
+        
+        dispatch_async(dispatch_get_main_queue(), ^{
+            switch (state) {
+                case AFOperationExecutingState:
+                    [[NSNotificationCenter defaultCenter] postNotificationName:AFNetworkingOperationDidStartNotification object:self];
+                    break;
+                case AFOperationFinishedState:
+                    [[NSNotificationCenter defaultCenter] postNotificationName:AFNetworkingOperationDidFinishNotification object:self];
+                    break;
+                default:
+                    break;
+            }
+        });
     }
     [self.lock unlock];
 }