diff --git a/src/objective-c/tests/GRPCClientTests.m b/src/objective-c/tests/GRPCClientTests.m
index 9a8d4253241..2eca7bf5498 100644
--- a/src/objective-c/tests/GRPCClientTests.m
+++ b/src/objective-c/tests/GRPCClientTests.m
@@ -48,9 +48,9 @@ static NSString * const kPackage = @"grpc.testing";
 static NSString * const kService = @"TestService";
 static NSString * const kRemoteSSLHost = @"grpc-test.sandbox.googleapis.com";
 
-static ProtoMethod *kInexistentMethod;
-static ProtoMethod *kEmptyCallMethod;
-static ProtoMethod *kUnaryCallMethod;
+static GRPCProtoMethod *kInexistentMethod;
+static GRPCProtoMethod *kEmptyCallMethod;
+static GRPCProtoMethod *kUnaryCallMethod;
 
 /** Observer class for testing that responseMetadata is KVO-compliant */
 @interface PassthroughObserver : NSObject
@@ -109,13 +109,13 @@ static ProtoMethod *kUnaryCallMethod;
   [GRPCCall useInsecureConnectionsForHost:kHostAddress];
 
   // This method isn't implemented by the remote server.
-  kInexistentMethod = [[ProtoMethod alloc] initWithPackage:kPackage
+  kInexistentMethod = [[GRPCProtoMethod alloc] initWithPackage:kPackage
                                                    service:kService
                                                     method:@"Inexistent"];
-  kEmptyCallMethod = [[ProtoMethod alloc] initWithPackage:kPackage
+  kEmptyCallMethod = [[GRPCProtoMethod alloc] initWithPackage:kPackage
                                                   service:kService
                                                    method:@"EmptyCall"];
-  kUnaryCallMethod = [[ProtoMethod alloc] initWithPackage:kPackage
+  kUnaryCallMethod = [[GRPCProtoMethod alloc] initWithPackage:kPackage
                                                   service:kService
                                                    method:@"UnaryCall"];
 }
@@ -303,7 +303,7 @@ static ProtoMethod *kUnaryCallMethod;
 
   // Try to set parameters to nil for GRPCCall. This should cause an exception
   @try {
-    GRPCCall *call = [[GRPCCall alloc] initWithHost:nil
+    GRPCCall *call __unused = [[GRPCCall alloc] initWithHost:nil
                                                path:nil
                                      requestsWriter:nil];
     XCTFail(@"Did not receive an exception when parameters are nil");
@@ -316,7 +316,7 @@ static ProtoMethod *kUnaryCallMethod;
   GRXWriter *requestsWriter = [GRXWriter emptyWriter];
   [requestsWriter finishWithError:nil];
   @try {
-    GRPCCall *call = [[GRPCCall alloc] initWithHost:kHostAddress
+    GRPCCall *call __unused = [[GRPCCall alloc] initWithHost:kHostAddress
                                                path:kUnaryCallMethod.HTTPPath
                                      requestsWriter:requestsWriter];
     XCTFail(@"Did not receive an exception when GRXWriter has incorrect state.");
diff --git a/src/objective-c/tests/InteropTests.m b/src/objective-c/tests/InteropTests.m
index 781c500f73e..60a83259fa6 100644
--- a/src/objective-c/tests/InteropTests.m
+++ b/src/objective-c/tests/InteropTests.m
@@ -58,7 +58,7 @@
                  requestedResponseSize:(NSNumber *)responseSize {
   RMTStreamingOutputCallRequest *request = [self message];
   RMTResponseParameters *parameters = [RMTResponseParameters message];
-  parameters.size = responseSize.integerValue;
+  parameters.size = (int)responseSize.integerValue;
   [request.responseParametersArray addObject:parameters];
   request.payload.body = [NSMutableData dataWithLength:payloadSize.unsignedIntegerValue];
   return request;
@@ -80,7 +80,9 @@
 
 #pragma mark Tests
 
+#ifdef GRPC_COMPILE_WITH_CRONET
 static cronet_engine *cronetEngine = NULL;
+#endif
 
 @implementation InteropTests {
   RMTTestService *_service;
@@ -186,7 +188,7 @@ static cronet_engine *cronetEngine = NULL;
   RMTStreamingOutputCallRequest *request = [RMTStreamingOutputCallRequest message];
   for (NSNumber *size in expectedSizes) {
     RMTResponseParameters *parameters = [RMTResponseParameters message];
-    parameters.size = [size integerValue];
+    parameters.size = (int)[size integerValue];
     [request.responseParametersArray addObject:parameters];
   }
 
@@ -282,7 +284,7 @@ static cronet_engine *cronetEngine = NULL;
   // A buffered pipe to which we never write any value acts as a writer that just hangs.
   GRXBufferedPipe *requestsBuffer = [[GRXBufferedPipe alloc] init];
 
-  ProtoRPC *call = [_service RPCToStreamingInputCallWithRequestsWriter:requestsBuffer
+  GRPCProtoCall *call = [_service RPCToStreamingInputCallWithRequestsWriter:requestsBuffer
                                                                handler:^(RMTStreamingInputCallResponse *response,
                                                                          NSError *error) {
     XCTAssertEqual(error.code, GRPC_STATUS_CANCELLED);
@@ -313,7 +315,7 @@ static cronet_engine *cronetEngine = NULL;
 
   [requestsBuffer writeValue:request];
 
-  __block ProtoRPC *call =
+  __block GRPCProtoCall *call =
       [_service RPCToFullDuplexCallWithRequestsWriter:requestsBuffer
                                          eventHandler:^(BOOL done,
                                                         RMTStreamingOutputCallResponse *response,
diff --git a/src/objective-c/tests/Tests.xcodeproj/project.pbxproj b/src/objective-c/tests/Tests.xcodeproj/project.pbxproj
index b0429617c01..59a6af2e11e 100644
--- a/src/objective-c/tests/Tests.xcodeproj/project.pbxproj
+++ b/src/objective-c/tests/Tests.xcodeproj/project.pbxproj
@@ -823,6 +823,7 @@
 					"$(inherited)",
 				);
 				GCC_SYMBOLS_PRIVATE_EXTERN = NO;
+				GCC_TREAT_WARNINGS_AS_ERRORS = YES;
 				GCC_WARN_64_TO_32_BIT_CONVERSION = YES;
 				GCC_WARN_ABOUT_RETURN_TYPE = YES_ERROR;
 				GCC_WARN_UNDECLARED_SELECTOR = YES;
@@ -859,6 +860,7 @@
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
 				GCC_C_LANGUAGE_STANDARD = gnu99;
 				GCC_NO_COMMON_BLOCKS = YES;
+				GCC_TREAT_WARNINGS_AS_ERRORS = YES;
 				GCC_WARN_64_TO_32_BIT_CONVERSION = YES;
 				GCC_WARN_ABOUT_RETURN_TYPE = YES_ERROR;
 				GCC_WARN_UNDECLARED_SELECTOR = YES;
@@ -875,6 +877,7 @@
 		635697DC1B14FC11007A7283 /* Debug */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				GCC_TREAT_WARNINGS_AS_ERRORS = YES;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SKIP_INSTALL = YES;
 			};
@@ -883,6 +886,7 @@
 		635697DD1B14FC11007A7283 /* Release */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				GCC_TREAT_WARNINGS_AS_ERRORS = YES;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SKIP_INSTALL = YES;
 			};