diff --git a/SDWebImage/MKAnnotationView+WebCache.m b/SDWebImage/MKAnnotationView+WebCache.m
index cc75da00..e175ef3e 100644
--- a/SDWebImage/MKAnnotationView+WebCache.m
+++ b/SDWebImage/MKAnnotationView+WebCache.m
@@ -62,7 +62,7 @@ static char imageURLKey;
         [self sd_setImageLoadOperation:operation forKey:@"MKAnnotationViewImage"];
     } else {
         dispatch_main_async_safe(^{
-            NSError *error = [NSError errorWithDomain:@"SDWebImageErrorDomain" code:-1 userInfo:@{NSLocalizedDescriptionKey : @"Trying to load a nil url"}];
+            NSError *error = [NSError errorWithDomain:SDWebImageErrorDomain code:-1 userInfo:@{NSLocalizedDescriptionKey : @"Trying to load a nil url"}];
             if (completedBlock) {
                 completedBlock(nil, error, SDImageCacheTypeNone, url);
             }
diff --git a/SDWebImage/SDWebImageCompat.h b/SDWebImage/SDWebImageCompat.h
index a0555fdf..700007cd 100644
--- a/SDWebImage/SDWebImageCompat.h
+++ b/SDWebImage/SDWebImageCompat.h
@@ -55,6 +55,8 @@ extern UIImage *SDScaledImageForKey(NSString *key, UIImage *image);
 
 typedef void(^SDWebImageNoParamsBlock)();
 
+extern NSString *const SDWebImageErrorDomain;
+
 #define dispatch_main_sync_safe(block)\
     if ([NSThread isMainThread]) {\
         block();\
diff --git a/SDWebImage/SDWebImageCompat.m b/SDWebImage/SDWebImageCompat.m
index 8c7d345a..562bacd2 100644
--- a/SDWebImage/SDWebImageCompat.m
+++ b/SDWebImage/SDWebImageCompat.m
@@ -43,3 +43,5 @@ inline UIImage *SDScaledImageForKey(NSString *key, UIImage *image) {
         return image;
     }
 }
+
+NSString *const SDWebImageErrorDomain = @"SDWebImageErrorDomain";
diff --git a/SDWebImage/SDWebImageDownloaderOperation.m b/SDWebImage/SDWebImageDownloaderOperation.m
index 025a0804..cc75d5ed 100644
--- a/SDWebImage/SDWebImageDownloaderOperation.m
+++ b/SDWebImage/SDWebImageDownloaderOperation.m
@@ -376,7 +376,7 @@
                 }
             }
             if (CGSizeEqualToSize(image.size, CGSizeZero)) {
-                completionBlock(nil, nil, [NSError errorWithDomain:@"SDWebImageErrorDomain" code:0 userInfo:@{NSLocalizedDescriptionKey : @"Downloaded image has 0 pixels"}], YES);
+                completionBlock(nil, nil, [NSError errorWithDomain:SDWebImageErrorDomain code:0 userInfo:@{NSLocalizedDescriptionKey : @"Downloaded image has 0 pixels"}], YES);
             }
             else {
                 completionBlock(image, self.imageData, nil, YES);
diff --git a/SDWebImage/UIButton+WebCache.m b/SDWebImage/UIButton+WebCache.m
index 8e076ae5..677989fe 100644
--- a/SDWebImage/UIButton+WebCache.m
+++ b/SDWebImage/UIButton+WebCache.m
@@ -57,7 +57,7 @@ static char imageURLStorageKey;
         [self.imageURLStorage removeObjectForKey:@(state)];
         
         dispatch_main_async_safe(^{
-            NSError *error = [NSError errorWithDomain:@"SDWebImageErrorDomain" code:-1 userInfo:@{NSLocalizedDescriptionKey : @"Trying to load a nil url"}];
+            NSError *error = [NSError errorWithDomain:SDWebImageErrorDomain code:-1 userInfo:@{NSLocalizedDescriptionKey : @"Trying to load a nil url"}];
             if (completedBlock) {
                 completedBlock(nil, error, SDImageCacheTypeNone, url);
             }
@@ -128,7 +128,7 @@ static char imageURLStorageKey;
         [self sd_setBackgroundImageLoadOperation:operation forState:state];
     } else {
         dispatch_main_async_safe(^{
-            NSError *error = [NSError errorWithDomain:@"SDWebImageErrorDomain" code:-1 userInfo:@{NSLocalizedDescriptionKey : @"Trying to load a nil url"}];
+            NSError *error = [NSError errorWithDomain:SDWebImageErrorDomain code:-1 userInfo:@{NSLocalizedDescriptionKey : @"Trying to load a nil url"}];
             if (completedBlock) {
                 completedBlock(nil, error, SDImageCacheTypeNone, url);
             }
diff --git a/SDWebImage/UIImageView+HighlightedWebCache.m b/SDWebImage/UIImageView+HighlightedWebCache.m
index ae73610f..d77c17b5 100644
--- a/SDWebImage/UIImageView+HighlightedWebCache.m
+++ b/SDWebImage/UIImageView+HighlightedWebCache.m
@@ -51,7 +51,7 @@
         [self sd_setImageLoadOperation:operation forKey:UIImageViewHighlightedWebCacheOperationKey];
     } else {
         dispatch_main_async_safe(^{
-            NSError *error = [NSError errorWithDomain:@"SDWebImageErrorDomain" code:-1 userInfo:@{NSLocalizedDescriptionKey : @"Trying to load a nil url"}];
+            NSError *error = [NSError errorWithDomain:SDWebImageErrorDomain code:-1 userInfo:@{NSLocalizedDescriptionKey : @"Trying to load a nil url"}];
             if (completedBlock) {
                 completedBlock(nil, error, SDImageCacheTypeNone, url);
             }
diff --git a/SDWebImage/UIImageView+WebCache.m b/SDWebImage/UIImageView+WebCache.m
index 1e225eb0..b97cec6a 100644
--- a/SDWebImage/UIImageView+WebCache.m
+++ b/SDWebImage/UIImageView+WebCache.m
@@ -71,7 +71,7 @@ static char imageURLKey;
         [self sd_setImageLoadOperation:operation forKey:@"UIImageViewImageLoad"];
     } else {
         dispatch_main_async_safe(^{
-            NSError *error = [NSError errorWithDomain:@"SDWebImageErrorDomain" code:-1 userInfo:@{NSLocalizedDescriptionKey : @"Trying to load a nil url"}];
+            NSError *error = [NSError errorWithDomain:SDWebImageErrorDomain code:-1 userInfo:@{NSLocalizedDescriptionKey : @"Trying to load a nil url"}];
             if (completedBlock) {
                 completedBlock(nil, error, SDImageCacheTypeNone, url);
             }