diff --git a/src/objective-c/GRPCClient/private/GRPCWrappedCall.m b/src/objective-c/GRPCClient/private/GRPCWrappedCall.m
index 1a848a4b7c3..7d7e77f6ba0 100644
--- a/src/objective-c/GRPCClient/private/GRPCWrappedCall.m
+++ b/src/objective-c/GRPCClient/private/GRPCWrappedCall.m
@@ -292,6 +292,10 @@
       gpr_free(ops_array);
 
       NSAssert(error == GRPC_CALL_OK, @"Error starting a batch of operations: %i", error);
+      // To avoid compiler complaint when NSAssert is disabled.
+      if (error != GRPC_CALL_OK) {
+        return;
+      }
     }
   }
 }
diff --git a/src/objective-c/ProtoRPC/ProtoService.h b/src/objective-c/ProtoRPC/ProtoService.h
index d76e96ce2a6..900ec8d0e1e 100644
--- a/src/objective-c/ProtoRPC/ProtoService.h
+++ b/src/objective-c/ProtoRPC/ProtoService.h
@@ -25,7 +25,7 @@
 @class GRPCProtoCall;
 @class GRPCUnaryProtoCall;
 @class GRPCStreamingProtoCall;
-@protocol GRPCProtoResponseCallbacks;
+@protocol GRPCProtoResponseHandler;
 
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wnullability-completeness"
@@ -49,12 +49,12 @@ __attribute__((deprecated("Please use GRPCProtoService."))) @interface ProtoServ
 
 - (nullable GRPCUnaryProtoCall *)RPCToMethod:(nonnull NSString *)method
                                      message:(nonnull id)message
-                             responseHandler:(nonnull id<GRPCProtoResponseCallbacks>)handler
+                             responseHandler:(nonnull id<GRPCProtoResponseHandler>)handler
                                  callOptions:(nullable GRPCCallOptions *)callOptions
                                responseClass:(nonnull Class)responseClass;
 
 - (nullable GRPCStreamingProtoCall *)RPCToMethod:(nonnull NSString *)method
-                                 responseHandler:(nonnull id<GRPCProtoResponseCallbacks>)handler
+                                 responseHandler:(nonnull id<GRPCProtoResponseHandler>)handler
                                      callOptions:(nullable GRPCCallOptions *)callOptions
                                    responseClass:(nonnull Class)responseClass;
 
diff --git a/src/objective-c/ProtoRPC/ProtoService.m b/src/objective-c/ProtoRPC/ProtoService.m
index b7c7fadbcf0..80a1f2f226c 100644
--- a/src/objective-c/ProtoRPC/ProtoService.m
+++ b/src/objective-c/ProtoRPC/ProtoService.m
@@ -58,11 +58,14 @@
   return self;
 }
 
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wobjc-designated-initializers"
+// Do not call designated initializer here due to nullability incompatibility. This method is from
+// old API and does not assert on nullability of the parameters.
+
 - (instancetype)initWithHost:(NSString *)host
                  packageName:(NSString *)packageName
                  serviceName:(NSString *)serviceName {
-  // Do not call designated initializer here due to nullability incompatibility. This method is from
-  // old API and does not assert on nullability of the parameters.
   if ((self = [super init])) {
     _host = [host copy];
     _packageName = [packageName copy];
@@ -72,6 +75,8 @@
   return self;
 }
 
+#pragma clang diagnostic pop
+
 - (GRPCProtoCall *)RPCToMethod:(NSString *)method
                 requestsWriter:(GRXWriter *)requestsWriter
                  responseClass:(Class)responseClass
@@ -87,7 +92,7 @@
 
 - (GRPCUnaryProtoCall *)RPCToMethod:(NSString *)method
                             message:(id)message
-                    responseHandler:(id<GRPCProtoResponseCallbacks>)handler
+                    responseHandler:(id<GRPCProtoResponseHandler>)handler
                         callOptions:(GRPCCallOptions *)callOptions
                       responseClass:(Class)responseClass {
   GRPCProtoMethod *methodName =
@@ -104,7 +109,7 @@
 }
 
 - (GRPCStreamingProtoCall *)RPCToMethod:(NSString *)method
-                        responseHandler:(id<GRPCProtoResponseCallbacks>)handler
+                        responseHandler:(id<GRPCProtoResponseHandler>)handler
                             callOptions:(GRPCCallOptions *)callOptions
                           responseClass:(Class)responseClass {
   GRPCProtoMethod *methodName =