diff --git a/SDWebImage/NSButton+WebCache.h b/SDWebImage/NSButton+WebCache.h
index 57f7115e..33f84ba0 100644
--- a/SDWebImage/NSButton+WebCache.h
+++ b/SDWebImage/NSButton+WebCache.h
@@ -19,7 +19,7 @@
 /**
  * Get the current image URL.
  */
-- (nullable NSURL *)sd_currentImageURL;
+@property (nonatomic, strong, readonly, nullable) NSURL *sd_currentImageURL;
 
 /**
  * Set the button `image` with an `url`.
@@ -133,7 +133,7 @@
 /**
  * Get the current alternateImage URL.
  */
-- (nullable NSURL *)sd_currentAlternateImageURL;
+@property (nonatomic, strong, readonly, nullable) NSURL *sd_currentAlternateImageURL;
 
 /**
  * Set the button `alternateImage` with an `url`.
diff --git a/SDWebImage/SDWebImageTransition.h b/SDWebImage/SDWebImageTransition.h
index 01925947..0c364ea0 100644
--- a/SDWebImage/SDWebImageTransition.h
+++ b/SDWebImage/SDWebImageTransition.h
@@ -67,8 +67,6 @@ typedef void (^SDWebImageTransitionCompletionBlock)(BOOL finished);
 
 @interface SDWebImageTransition (Conveniences)
 
-// class property is available in Xcode 8. We will drop the Xcode 7.3 support in 5.x
-#if __has_feature(objc_class_property)
 /// Fade transition.
 @property (nonatomic, class, nonnull, readonly) SDWebImageTransition *fadeTransition;
 /// Flip from left transition.
@@ -83,15 +81,6 @@ typedef void (^SDWebImageTransitionCompletionBlock)(BOOL finished);
 @property (nonatomic, class, nonnull, readonly) SDWebImageTransition *curlUpTransition;
 /// Curl down transition.
 @property (nonatomic, class, nonnull, readonly) SDWebImageTransition *curlDownTransition;
-#else
-+ (nonnull instancetype)fadeTransition;
-+ (nonnull instancetype)flipFromLeftTransition;
-+ (nonnull instancetype)flipFromRightTransition;
-+ (nonnull instancetype)flipFromTopTransition;
-+ (nonnull instancetype)flipFromBottomTransition;
-+ (nonnull instancetype)curlUpTransition;
-+ (nonnull instancetype)curlDownTransition;
-#endif
 
 @end
 
diff --git a/SDWebImage/UIButton+WebCache.h b/SDWebImage/UIButton+WebCache.h
index 61fada62..ffe80651 100644
--- a/SDWebImage/UIButton+WebCache.h
+++ b/SDWebImage/UIButton+WebCache.h
@@ -22,7 +22,7 @@
 /**
  * Get the current image URL.
  */
-- (nullable NSURL *)sd_currentImageURL;
+@property (nonatomic, strong, readonly, nullable) NSURL *sd_currentImageURL;
 
 /**
  * Get the image URL for a control state.
@@ -133,7 +133,7 @@
 /**
  * Get the current background image URL.
  */
-- (nullable NSURL *)sd_currentBackgroundImageURL;
+@property (nonatomic, strong, readonly, nullable) NSURL *sd_currentBackgroundImageURL;
 
 /**
  * Get the background image URL for a control state.