diff --git a/SDWebImage/SDWebImageDownloaderOperation.m b/SDWebImage/SDWebImageDownloaderOperation.m
index 7996b16..f317a0f 100644
--- a/SDWebImage/SDWebImageDownloaderOperation.m
+++ b/SDWebImage/SDWebImageDownloaderOperation.m
@@ -146,12 +146,17 @@
     {
         dispatch_async(self.queue, ^
         {
-            self.expectedSize = response.expectedContentLength > 0 ? (NSUInteger)response.expectedContentLength : 0;
-            self.imageData = [NSMutableData.alloc initWithCapacity:self.expectedSize];
-            if (self.progressBlock)
+            NSUInteger expected = response.expectedContentLength > 0 ? (NSUInteger)response.expectedContentLength : 0;
+            self.imageData = [NSMutableData.alloc initWithCapacity:expected];
+            self.expectedSize = expected;
+
+            dispatch_async(dispatch_get_main_queue(), ^
             {
-                self.progressBlock(0, self.expectedSize);
-            }
+                if (self.progressBlock)
+                {
+                    self.progressBlock(0, expected);
+                }
+            });
         });
     }
     else
@@ -238,10 +243,13 @@
 
             CFRelease(imageSource);
         }
-        if (self.progressBlock)
+        dispatch_async(dispatch_get_main_queue(), ^
         {
-            self.progressBlock(self.imageData.length, self.expectedSize);
-        }
+            if (self.progressBlock)
+            {
+                self.progressBlock(self.imageData.length, self.expectedSize);
+            }
+        });
     });
 }
 
diff --git a/SDWebImage/SDWebImageManager.m b/SDWebImage/SDWebImageManager.m
index 314067f..380ea19 100644
--- a/SDWebImage/SDWebImageManager.m
+++ b/SDWebImage/SDWebImageManager.m
@@ -97,14 +97,7 @@
             SDWebImageDownloaderOptions downloaderOptions = 0;
             if (options & SDWebImageLowPriority) downloaderOptions |= SDWebImageDownloaderLowPriority;
             if (options & SDWebImageProgressiveDownload) downloaderOptions |= SDWebImageDownloaderProgressiveDownload;
-            __block id<SDWebImageOperation> subOperation = [self.imageDownloader downloadImageWithURL:url options:downloaderOptions progress:^(NSUInteger receivedSize, long long expectedSize)
-            {
-                dispatch_async(dispatch_get_main_queue(), ^
-                {
-                    progressBlock(receivedSize, expectedSize);
-                });
-            }
-            completed:^(UIImage *downloadedImage, NSData *data, NSError *error, BOOL finished)
+            __block id<SDWebImageOperation> subOperation = [self.imageDownloader downloadImageWithURL:url options:downloaderOptions progress:progressBlock completed:^(UIImage *downloadedImage, NSData *data, NSError *error, BOOL finished)
             {
                 dispatch_async(dispatch_get_main_queue(), ^
                 {