diff --git a/SDWebImage/SDAnimatedImageRep.m b/SDWebImage/SDAnimatedImageRep.m
index f0907d5c..40e57855 100644
--- a/SDWebImage/SDAnimatedImageRep.m
+++ b/SDWebImage/SDAnimatedImageRep.m
@@ -18,20 +18,42 @@
 
 @end
 
-@interface SDAnimatedImageRep ()
+@implementation SDAnimatedImageRep {
+    CGImageSourceRef _imageSource;
+}
 
-@property (nonatomic, assign, readonly, nullable) CGImageSourceRef imageSource;
+- (void)dealloc {
+    if (_imageSource) {
+        CFRelease(_imageSource);
+        _imageSource = NULL;
+    }
+}
 
-@end
+// `NSBitmapImageRep`'s `imageRepWithData:` is not designed initlizer
++ (instancetype)imageRepWithData:(NSData *)data {
+    SDAnimatedImageRep *imageRep = [[SDAnimatedImageRep alloc] initWithData:data];
+    return imageRep;
+}
 
-@implementation SDAnimatedImageRep
+// We should override init method for `NSBitmapImageRep` to do initlize about animated image format
+- (instancetype)initWithData:(NSData *)data {
+    self = [super initWithData:data];
+    if (self) {
+        CGImageSourceRef imageSource = CGImageSourceCreateWithData((__bridge CFDataRef) data, NULL);
+        if (!imageSource) {
+            return self;
+        }
+        _imageSource = imageSource;
+    }
+    return self;
+}
 
 // `NSBitmapImageRep` will use `kCGImagePropertyGIFDelayTime` whenever you call `setProperty:withValue:` with `NSImageCurrentFrame` to change the current frame. We override it and use the actual `kCGImagePropertyGIFUnclampedDelayTime` if need.
 - (void)setProperty:(NSBitmapImageRepPropertyKey)property withValue:(id)value {
     [super setProperty:property withValue:value];
     if ([property isEqualToString:NSImageCurrentFrame]) {
         // Access the image source
-        CGImageSourceRef imageSource = self.imageSource;
+        CGImageSourceRef imageSource = _imageSource;
         if (!imageSource) {
             return;
         }
@@ -54,13 +76,6 @@
     }
 }
 
-- (CGImageSourceRef)imageSource {
-    if (_tiffData) {
-        return (__bridge CGImageSourceRef)(_tiffData);
-    }
-    return NULL;
-}
-
 @end
 
 #endif