diff --git a/just_audio/ios/Classes/ConcatenatingAudioSource.h b/just_audio/ios/Classes/ConcatenatingAudioSource.h
index 7cabf48..9d9bf44 100644
--- a/just_audio/ios/Classes/ConcatenatingAudioSource.h
+++ b/just_audio/ios/Classes/ConcatenatingAudioSource.h
@@ -5,7 +5,7 @@
 
 @property (readonly, nonatomic) int count;
 
-- (instancetype)initWithId:(NSString *)sid audioSources:(NSMutableArray<AudioSource *> *)audioSources shuffleOrder:(NSMutableArray<NSNumber *> *)shuffleOrder;
+- (instancetype)initWithId:(NSString *)sid audioSources:(NSMutableArray<AudioSource *> *)audioSources shuffleOrder:(NSArray<NSNumber *> *)shuffleOrder;
 - (void)insertSource:(AudioSource *)audioSource atIndex:(int)index;
 - (void)removeSourcesFromIndex:(int)start toIndex:(int)end;
 - (void)moveSourceFromIndex:(int)currentIndex toIndex:(int)newIndex;
diff --git a/just_audio/macos/Classes/ConcatenatingAudioSource.h b/just_audio/macos/Classes/ConcatenatingAudioSource.h
index c72bf67..51bd608 100644
--- a/just_audio/macos/Classes/ConcatenatingAudioSource.h
+++ b/just_audio/macos/Classes/ConcatenatingAudioSource.h
@@ -5,7 +5,7 @@
 
 @property (readonly, nonatomic) int count;
 
-- (instancetype)initWithId:(NSString *)sid audioSources:(NSMutableArray<AudioSource *> *)audioSources shuffleOrder:(NSMutableArray<NSNumber *> *)shuffleOrder;
+- (instancetype)initWithId:(NSString *)sid audioSources:(NSMutableArray<AudioSource *> *)audioSources shuffleOrder:(NSArray<NSNumber *> *)shuffleOrder;
 - (void)insertSource:(AudioSource *)audioSource atIndex:(int)index;
 - (void)removeSourcesFromIndex:(int)start toIndex:(int)end;
 - (void)moveSourceFromIndex:(int)currentIndex toIndex:(int)newIndex;