diff --git a/AXAnimationChain/Classes/CoreAnimation/CAAnimation+Convertable.h b/AXAnimationChain/Classes/CoreAnimation/CAAnimation+Convertable.h
index d30f592..eb29c54 100644
--- a/AXAnimationChain/Classes/CoreAnimation/CAAnimation+Convertable.h
+++ b/AXAnimationChain/Classes/CoreAnimation/CAAnimation+Convertable.h
@@ -40,7 +40,7 @@ NS_ASSUME_NONNULL_BEGIN
 + (nullable instancetype)animationWithBasic:(nullable CABasicAnimation *)basicAnimation;
 /// Convert animation from CABasicAnimation using custom values function.
 ///
-+ (nullable instancetype)animationWithBasic:(nullable CABasicAnimation *)basicAnimation usingValuesFunction:(nullable double (^)(double t, double b, double c, double d))valuesFunction;
++ (nullable instancetype)animationWithBasic:(nullable CABasicAnimation *)basicAnimation usingValuesFunction:(CAKeyframeValuesFunction _Nullable)valuesFunction;
 /// Convert animation from SpringAnimation.
 ///
 /// @param animation spring animation to convert.
diff --git a/AXAnimationChain/Classes/CoreAnimation/CAAnimation+Convertable.m b/AXAnimationChain/Classes/CoreAnimation/CAAnimation+Convertable.m
index addc77e..0296cee 100644
--- a/AXAnimationChain/Classes/CoreAnimation/CAAnimation+Convertable.m
+++ b/AXAnimationChain/Classes/CoreAnimation/CAAnimation+Convertable.m
@@ -308,7 +308,7 @@ id CalculateToValueWithByValue(id value, id byValue, BOOL plus) {
 }
 
 @implementation CAKeyframeAnimation (Convertable)
-+ (instancetype)animationWithBasic:(CABasicAnimation *)basicAnimation usingValuesFunction:(double (^)(double, double, double, double))valuesFunction {
++ (instancetype)animationWithBasic:(CABasicAnimation *)basicAnimation usingValuesFunction:(CAKeyframeValuesFunction)valuesFunction {
     if (!basicAnimation) return nil;
     CAKeyframeAnimation *keyframe = [CAKeyframeAnimation animation];
     keyframe.beginTime = basicAnimation.beginTime;
@@ -476,6 +476,11 @@ + (instancetype)animationWithBasic:(CABasicAnimation *)animation {
 @end
 
 @implementation AXDecayAnimation (Convertable)
++ (instancetype)animationWithBasic:(CABasicAnimation *)basicAnimation usingValuesFunction:(CAKeyframeValuesFunction)valuesFunction {
+    if (!basicAnimation || ![basicAnimation isKindOfClass:CAKeyframeAnimation.class]) return nil;
+    return [super animationWithBasic:basicAnimation usingValuesFunction:valuesFunction];
+}
+
 + (instancetype)animationWithSpring:(AXCASpringAnimation *)animation {
     return [self animationWithBasic:animation];
 }