diff --git a/SDWebImage/MKAnnotationView+WebCache.h b/SDWebImage/MKAnnotationView+WebCache.h
index 334bc413..e7f99037 100644
--- a/SDWebImage/MKAnnotationView+WebCache.h
+++ b/SDWebImage/MKAnnotationView+WebCache.h
@@ -64,7 +64,7 @@
  *                       and takes the requested UIImage as first parameter. In case of error the image parameter
  *                       is nil and the second parameter may contain an NSError. The third parameter is a Boolean
  *                       indicating if the image was retrived from the local cache or from the network.
- *                       The forth parameter is the original image url.
+ *                       The fourth parameter is the original image url.
  */
 - (void)sd_setImageWithURL:(NSURL *)url completed:(SDWebImageCompletionBlock)completedBlock;
 
@@ -79,7 +79,7 @@
  *                       and takes the requested UIImage as first parameter. In case of error the image parameter
  *                       is nil and the second parameter may contain an NSError. The third parameter is a Boolean
  *                       indicating if the image was retrived from the local cache or from the network.
- *                       The forth parameter is the original image url.
+ *                       The fourth parameter is the original image url.
  */
 - (void)sd_setImageWithURL:(NSURL *)url placeholderImage:(UIImage *)placeholder completed:(SDWebImageCompletionBlock)completedBlock;
 
@@ -95,7 +95,7 @@
  *                       and takes the requested UIImage as first parameter. In case of error the image parameter
  *                       is nil and the second parameter may contain an NSError. The third parameter is a Boolean
  *                       indicating if the image was retrived from the local cache or from the network.
- *                       The forth parameter is the original image url.
+ *                       The fourth parameter is the original image url.
  */
 - (void)sd_setImageWithURL:(NSURL *)url placeholderImage:(UIImage *)placeholder options:(SDWebImageOptions)options completed:(SDWebImageCompletionBlock)completedBlock;
 
diff --git a/SDWebImage/UIButton+WebCache.h b/SDWebImage/UIButton+WebCache.h
index 5791deac..48ad0d53 100644
--- a/SDWebImage/UIButton+WebCache.h
+++ b/SDWebImage/UIButton+WebCache.h
@@ -71,7 +71,7 @@
  *                       and takes the requested UIImage as first parameter. In case of error the image parameter
  *                       is nil and the second parameter may contain an NSError. The third parameter is a Boolean
  *                       indicating if the image was retrived from the local cache or from the network.
- *                       The forth parameter is the original image url.
+ *                       The fourth parameter is the original image url.
  */
 - (void)sd_setImageWithURL:(NSURL *)url forState:(UIControlState)state completed:(SDWebImageCompletionBlock)completedBlock;
 
@@ -87,7 +87,7 @@
  *                       and takes the requested UIImage as first parameter. In case of error the image parameter
  *                       is nil and the second parameter may contain an NSError. The third parameter is a Boolean
  *                       indicating if the image was retrived from the local cache or from the network.
- *                       The forth parameter is the original image url.
+ *                       The fourth parameter is the original image url.
  */
 - (void)sd_setImageWithURL:(NSURL *)url forState:(UIControlState)state placeholderImage:(UIImage *)placeholder completed:(SDWebImageCompletionBlock)completedBlock;
 
@@ -104,7 +104,7 @@
  *                       and takes the requested UIImage as first parameter. In case of error the image parameter
  *                       is nil and the second parameter may contain an NSError. The third parameter is a Boolean
  *                       indicating if the image was retrived from the local cache or from the network.
- *                       The forth parameter is the original image url.
+ *                       The fourth parameter is the original image url.
  */
 - (void)sd_setImageWithURL:(NSURL *)url forState:(UIControlState)state placeholderImage:(UIImage *)placeholder options:(SDWebImageOptions)options completed:(SDWebImageCompletionBlock)completedBlock;
 
@@ -153,7 +153,7 @@
  *                       and takes the requested UIImage as first parameter. In case of error the image parameter
  *                       is nil and the second parameter may contain an NSError. The third parameter is a Boolean
  *                       indicating if the image was retrived from the local cache or from the network.
- *                       The forth parameter is the original image url.
+ *                       The fourth parameter is the original image url.
  */
 - (void)sd_setBackgroundImageWithURL:(NSURL *)url forState:(UIControlState)state completed:(SDWebImageCompletionBlock)completedBlock;
 
@@ -169,7 +169,7 @@
  *                       and takes the requested UIImage as first parameter. In case of error the image parameter
  *                       is nil and the second parameter may contain an NSError. The third parameter is a Boolean
  *                       indicating if the image was retrived from the local cache or from the network.
- *                       The forth parameter is the original image url.
+ *                       The fourth parameter is the original image url.
  */
 - (void)sd_setBackgroundImageWithURL:(NSURL *)url forState:(UIControlState)state placeholderImage:(UIImage *)placeholder completed:(SDWebImageCompletionBlock)completedBlock;
 
@@ -185,7 +185,7 @@
  *                       and takes the requested UIImage as first parameter. In case of error the image parameter
  *                       is nil and the second parameter may contain an NSError. The third parameter is a Boolean
  *                       indicating if the image was retrived from the local cache or from the network.
- *                       The forth parameter is the original image url.
+ *                       The fourth parameter is the original image url.
  */
 - (void)sd_setBackgroundImageWithURL:(NSURL *)url forState:(UIControlState)state placeholderImage:(UIImage *)placeholder options:(SDWebImageOptions)options completed:(SDWebImageCompletionBlock)completedBlock;
 
diff --git a/SDWebImage/UIImageView+HighlightedWebCache.h b/SDWebImage/UIImageView+HighlightedWebCache.h
index b6c520cb..57f708f1 100644
--- a/SDWebImage/UIImageView+HighlightedWebCache.h
+++ b/SDWebImage/UIImageView+HighlightedWebCache.h
@@ -44,7 +44,7 @@
  *                       and takes the requested UIImage as first parameter. In case of error the image parameter
  *                       is nil and the second parameter may contain an NSError. The third parameter is a Boolean
  *                       indicating if the image was retrived from the local cache or from the network.
- *                       The forth parameter is the original image url.
+ *                       The fourth parameter is the original image url.
  */
 - (void)sd_setHighlightedImageWithURL:(NSURL *)url completed:(SDWebImageCompletionBlock)completedBlock;
 
@@ -59,7 +59,7 @@
  *                       and takes the requested UIImage as first parameter. In case of error the image parameter
  *                       is nil and the second parameter may contain an NSError. The third parameter is a Boolean
  *                       indicating if the image was retrived from the local cache or from the network.
- *                       The forth parameter is the original image url.
+ *                       The fourth parameter is the original image url.
  */
 - (void)sd_setHighlightedImageWithURL:(NSURL *)url options:(SDWebImageOptions)options completed:(SDWebImageCompletionBlock)completedBlock;
 
@@ -75,7 +75,7 @@
  *                       and takes the requested UIImage as first parameter. In case of error the image parameter
  *                       is nil and the second parameter may contain an NSError. The third parameter is a Boolean
  *                       indicating if the image was retrived from the local cache or from the network.
- *                       The forth parameter is the original image url.
+ *                       The fourth parameter is the original image url.
  */
 - (void)sd_setHighlightedImageWithURL:(NSURL *)url options:(SDWebImageOptions)options progress:(SDWebImageDownloaderProgressBlock)progressBlock completed:(SDWebImageCompletionBlock)completedBlock;
 
diff --git a/SDWebImage/UIImageView+WebCache.h b/SDWebImage/UIImageView+WebCache.h
index c20c9ce1..e7489f43 100644
--- a/SDWebImage/UIImageView+WebCache.h
+++ b/SDWebImage/UIImageView+WebCache.h
@@ -93,7 +93,7 @@
  *                       and takes the requested UIImage as first parameter. In case of error the image parameter
  *                       is nil and the second parameter may contain an NSError. The third parameter is a Boolean
  *                       indicating if the image was retrived from the local cache or from the network.
- *                       The forth parameter is the original image url.
+ *                       The fourth parameter is the original image url.
  */
 - (void)sd_setImageWithURL:(NSURL *)url completed:(SDWebImageCompletionBlock)completedBlock;
 
@@ -108,7 +108,7 @@
  *                       and takes the requested UIImage as first parameter. In case of error the image parameter
  *                       is nil and the second parameter may contain an NSError. The third parameter is a Boolean
  *                       indicating if the image was retrived from the local cache or from the network.
- *                       The forth parameter is the original image url.
+ *                       The fourth parameter is the original image url.
  */
 - (void)sd_setImageWithURL:(NSURL *)url placeholderImage:(UIImage *)placeholder completed:(SDWebImageCompletionBlock)completedBlock;
 
@@ -124,7 +124,7 @@
  *                       and takes the requested UIImage as first parameter. In case of error the image parameter
  *                       is nil and the second parameter may contain an NSError. The third parameter is a Boolean
  *                       indicating if the image was retrived from the local cache or from the network.
- *                       The forth parameter is the original image url.
+ *                       The fourth parameter is the original image url.
  */
 - (void)sd_setImageWithURL:(NSURL *)url placeholderImage:(UIImage *)placeholder options:(SDWebImageOptions)options completed:(SDWebImageCompletionBlock)completedBlock;
 
@@ -141,7 +141,7 @@
  *                       and takes the requested UIImage as first parameter. In case of error the image parameter
  *                       is nil and the second parameter may contain an NSError. The third parameter is a Boolean
  *                       indicating if the image was retrived from the local cache or from the network.
- *                       The forth parameter is the original image url.
+ *                       The fourth parameter is the original image url.
  */
 - (void)sd_setImageWithURL:(NSURL *)url placeholderImage:(UIImage *)placeholder options:(SDWebImageOptions)options progress:(SDWebImageDownloaderProgressBlock)progressBlock completed:(SDWebImageCompletionBlock)completedBlock;
 
@@ -158,7 +158,7 @@
  *                       and takes the requested UIImage as first parameter. In case of error the image parameter
  *                       is nil and the second parameter may contain an NSError. The third parameter is a Boolean
  *                       indicating if the image was retrived from the local cache or from the network.
- *                       The forth parameter is the original image url.
+ *                       The fourth parameter is the original image url.
  */
 - (void)sd_setImageWithPreviousCachedImageWithURL:(NSURL *)url andPlaceholderImage:(UIImage *)placeholder options:(SDWebImageOptions)options progress:(SDWebImageDownloaderProgressBlock)progressBlock completed:(SDWebImageCompletionBlock)completedBlock;