diff --git a/src/objective-c/GRPCClient/private/GRPCChannelPool.h b/src/objective-c/GRPCClient/private/GRPCChannelPool.h
index 1984919fa75..5ceb0b6d821 100644
--- a/src/objective-c/GRPCClient/private/GRPCChannelPool.h
+++ b/src/objective-c/GRPCClient/private/GRPCChannelPool.h
@@ -49,7 +49,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (instancetype)init;
 
-- (instancetype)initWithChannelDestroyDelay:(NSTimeInterval)channelDestroyDelay;
+- (instancetype)initWithChannelDestroyDelay:(NSTimeInterval)channelDestroyDelay NS_DESIGNATED_INITIALIZER;
 
 /**
  * Return a channel with a particular configuration. If the channel does not exist, execute \a