diff --git a/src/objective-c/GRPCClient/GRPCCallOptions.h b/src/objective-c/GRPCClient/GRPCCallOptions.h
index e5befeb977f..4224f45c04e 100644
--- a/src/objective-c/GRPCClient/GRPCCallOptions.h
+++ b/src/objective-c/GRPCClient/GRPCCallOptions.h
@@ -81,7 +81,7 @@ NS_ASSUME_NONNULL_BEGIN
 /**
  * Initial metadata key-value pairs that should be included in the request.
  */
-@property(copy, readonly, nullable) GRPCMetadataDictionary *initialMetadata;
+@property(copy, readonly, nullable) NSDictionary *initialMetadata;
 
 // Channel parameters; take into account of channel signature.
 
@@ -134,7 +134,7 @@ NS_ASSUME_NONNULL_BEGIN
  * Specify channel args to be used for this call. For a list of channel args available, see
  * grpc/grpc_types.h
  */
-@property(copy, readonly, nullable) GRPCMetadataDictionary *additionalChannelArgs;
+@property(copy, readonly, nullable) NSDictionary *additionalChannelArgs;
 
 // Parameters for SSL authentication.
 
@@ -272,7 +272,7 @@ NS_ASSUME_NONNULL_BEGIN
 /**
  * Initial metadata key-value pairs that should be included in the request.
  */
-@property(copy, readwrite, nullable) GRPCMetadataDictionary *initialMetadata;
+@property(copy, readwrite, nullable) NSDictionary *initialMetadata;
 
 // Channel parameters; take into account of channel signature.
 
@@ -327,7 +327,7 @@ NS_ASSUME_NONNULL_BEGIN
  * Specify channel args to be used for this call. For a list of channel args available, see
  * grpc/grpc_types.h
  */
-@property(copy, readwrite, nullable) GRPCMetadataDictionary *additionalChannelArgs;
+@property(copy, readwrite, nullable) NSDictionary *additionalChannelArgs;
 
 // Parameters for SSL authentication.
 
diff --git a/src/objective-c/GRPCClient/GRPCCallOptions.m b/src/objective-c/GRPCClient/GRPCCallOptions.m
index 69a9e1ce903..cb916330040 100644
--- a/src/objective-c/GRPCClient/GRPCCallOptions.m
+++ b/src/objective-c/GRPCClient/GRPCCallOptions.m
@@ -25,7 +25,7 @@ static NSString *const kDefaultServerAuthority = nil;
 static const NSTimeInterval kDefaultTimeout = 0;
 static const BOOL kDefaultFlowControlEnabled = NO;
 static NSArray<id<GRPCInterceptorFactory>> *const kDefaultInterceptorFactories = nil;
-static GRPCMetadataDictionary *const kDefaultInitialMetadata = nil;
+static NSDictionary *const kDefaultInitialMetadata = nil;
 static NSString *const kDefaultUserAgentPrefix = nil;
 static NSString *const kDefaultUserAgentSuffix = nil;
 static const NSUInteger kDefaultResponseSizeLimit = 0;
@@ -36,7 +36,7 @@ static const NSTimeInterval kDefaultKeepaliveTimeout = 0;
 static const NSTimeInterval kDefaultConnectMinTimeout = 0;
 static const NSTimeInterval kDefaultConnectInitialBackoff = 0;
 static const NSTimeInterval kDefaultConnectMaxBackoff = 0;
-static GRPCMetadataDictionary *const kDefaultAdditionalChannelArgs = nil;
+static NSDictionary *const kDefaultAdditionalChannelArgs = nil;
 static NSString *const kDefaultPEMRootCertificates = nil;
 static NSString *const kDefaultPEMPrivateKey = nil;
 static NSString *const kDefaultPEMCertificateChain = nil;
@@ -68,7 +68,7 @@ static BOOL areObjectsEqual(id obj1, id obj2) {
   NSArray<id<GRPCInterceptorFactory>> *_interceptorFactories;
   NSString *_oauth2AccessToken;
   id<GRPCAuthorizationProtocol> _authTokenProvider;
-  GRPCMetadataDictionary *_initialMetadata;
+  NSDictionary *_initialMetadata;
   NSString *_userAgentPrefix;
   NSString *_userAgentSuffix;
   NSUInteger _responseSizeLimit;
@@ -79,7 +79,7 @@ static BOOL areObjectsEqual(id obj1, id obj2) {
   NSTimeInterval _connectMinTimeout;
   NSTimeInterval _connectInitialBackoff;
   NSTimeInterval _connectMaxBackoff;
-  GRPCMetadataDictionary *_additionalChannelArgs;
+  NSDictionary *_additionalChannelArgs;
   NSString *_PEMRootCertificates;
   NSString *_PEMPrivateKey;
   NSString *_PEMCertificateChain;
@@ -155,7 +155,7 @@ static BOOL areObjectsEqual(id obj1, id obj2) {
                    interceptorFactories:(NSArray<id<GRPCInterceptorFactory>> *)interceptorFactories
                       oauth2AccessToken:(NSString *)oauth2AccessToken
                       authTokenProvider:(id<GRPCAuthorizationProtocol>)authTokenProvider
-                        initialMetadata:(GRPCMetadataDictionary *)initialMetadata
+                        initialMetadata:(NSDictionary *)initialMetadata
                         userAgentPrefix:(NSString *)userAgentPrefix
                         userAgentSuffix:(NSString *)userAgentSuffix
                       responseSizeLimit:(NSUInteger)responseSizeLimit
@@ -166,7 +166,7 @@ static BOOL areObjectsEqual(id obj1, id obj2) {
                       connectMinTimeout:(NSTimeInterval)connectMinTimeout
                   connectInitialBackoff:(NSTimeInterval)connectInitialBackoff
                       connectMaxBackoff:(NSTimeInterval)connectMaxBackoff
-                  additionalChannelArgs:(GRPCMetadataDictionary *)additionalChannelArgs
+                  additionalChannelArgs:(NSDictionary *)additionalChannelArgs
                     PEMRootCertificates:(NSString *)PEMRootCertificates
                           PEMPrivateKey:(NSString *)PEMPrivateKey
                     PEMCertificateChain:(NSString *)PEMCertificateChain
@@ -486,7 +486,7 @@ static BOOL areObjectsEqual(id obj1, id obj2) {
   _authTokenProvider = authTokenProvider;
 }
 
-- (void)setInitialMetadata:(GRPCMetadataDictionary *)initialMetadata {
+- (void)setInitialMetadata:(NSDictionary *)initialMetadata {
   _initialMetadata = [[NSDictionary alloc] initWithDictionary:initialMetadata copyItems:YES];
 }
 
@@ -550,7 +550,7 @@ static BOOL areObjectsEqual(id obj1, id obj2) {
   }
 }
 
-- (void)setAdditionalChannelArgs:(GRPCMetadataDictionary *)additionalChannelArgs {
+- (void)setAdditionalChannelArgs:(NSDictionary *)additionalChannelArgs {
   _additionalChannelArgs = [[NSDictionary alloc] initWithDictionary:additionalChannelArgs
                                                           copyItems:YES];
 }
diff --git a/src/objective-c/GRPCClient/GRPCTypes.h b/src/objective-c/GRPCClient/GRPCTypes.h
index 5feda614449..812f3460f75 100644
--- a/src/objective-c/GRPCClient/GRPCTypes.h
+++ b/src/objective-c/GRPCClient/GRPCTypes.h
@@ -192,6 +192,3 @@ typedef char* _Nonnull GRPCTransportID;
 - (void)getTokenWithHandler:(void (^_Nonnull)(NSString* _Nullable token))handler;
 
 @end
-
-/** gRPC metadata dictionary typedef */
-typedef NSDictionary<NSString*, id<NSCopying>> GRPCMetadataDictionary;