diff --git a/AFNetworking/AFHTTPClient.m b/AFNetworking/AFHTTPClient.m
index 96a7060..e3439da 100644
--- a/AFNetworking/AFHTTPClient.m
+++ b/AFNetworking/AFHTTPClient.m
@@ -566,8 +566,9 @@ static void AFNetworkReachabilityReleaseCallback(const void *info) {}
     
     for (AFHTTPRequestOperation *operation in operations) {
         AFCompletionBlock originalCompletionBlock = [operation.completionBlock copy];
+		__weak AFHTTPRequestOperation *weakOperation = operation;
         operation.completionBlock = ^{
-            dispatch_queue_t queue = operation.successCallbackQueue ?: dispatch_get_main_queue();
+            dispatch_queue_t queue = weakOperation.successCallbackQueue ?: dispatch_get_main_queue();
             dispatch_group_async(dispatchGroup, queue, ^{
                 if (originalCompletionBlock) {
                     originalCompletionBlock();
diff --git a/AFNetworking/AFImageRequestOperation.m b/AFNetworking/AFImageRequestOperation.m
index f4f724a..5c24c79 100644
--- a/AFNetworking/AFImageRequestOperation.m
+++ b/AFNetworking/AFImageRequestOperation.m
@@ -82,7 +82,7 @@ static dispatch_queue_t image_request_operation_processing_queue() {
                 dispatch_async(image_request_operation_processing_queue(), ^(void) {
                     UIImage *processedImage = imageProcessingBlock(image);
 
-                    dispatch_async(requestOperation.successCallbackQueue ?: dispatch_get_main_queue(), ^(void) {
+                    dispatch_async(operation.successCallbackQueue ?: dispatch_get_main_queue(), ^(void) {
                         success(operation.request, operation.response, processedImage);
                     });
                 });
@@ -113,7 +113,7 @@ static dispatch_queue_t image_request_operation_processing_queue() {
                 dispatch_async(image_request_operation_processing_queue(), ^(void) {
                     NSImage *processedImage = imageProcessingBlock(image);
 
-                    dispatch_async(requestOperation.successCallbackQueue ?: dispatch_get_main_queue(), ^(void) {
+                    dispatch_async(operation.successCallbackQueue ?: dispatch_get_main_queue(), ^(void) {
                         success(operation.request, operation.response, processedImage);
                     });
                 });