diff --git a/AFNetworking/AFImageRequestOperation.m b/AFNetworking/AFImageRequestOperation.m
index 2154124..f149ebb 100644
--- a/AFNetworking/AFImageRequestOperation.m
+++ b/AFNetworking/AFImageRequestOperation.m
@@ -78,7 +78,7 @@ static UIImage * AFInflatedImageFromResponseWithDataAtScale(NSHTTPURLResponse *r
     size_t width = CGImageGetWidth(imageRef);
     size_t height = CGImageGetHeight(imageRef);
     size_t bitsPerComponent = CGImageGetBitsPerComponent(imageRef);
-    size_t bytesPerRow = NULL; // CGImageGetBytesPerRow() calculates incorrectly in iOS 5.0, so defer to CGBitmapContextCreate()
+    size_t bytesPerRow = 0; // CGImageGetBytesPerRow() calculates incorrectly in iOS 5.0, so defer to CGBitmapContextCreate()
     CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
     CGBitmapInfo bitmapInfo = CGImageGetBitmapInfo(imageRef);