diff --git a/Libraries/Utilities/HMRClient.js b/Libraries/Utilities/HMRClient.js
index 08c0f4e432eb44..a86f6c94038caf 100644
--- a/Libraries/Utilities/HMRClient.js
+++ b/Libraries/Utilities/HMRClient.js
@@ -281,7 +281,8 @@ function registerBundleEntryPoints(client) {
 
 function dismissRedbox() {
   if (
-    Platform.OS === 'ios' &&
+    (Platform.OS === 'ios' ||
+      Platform.OS === 'macos') /* TODO(macOS ISS#2323203) */ &&
     NativeRedBox != null &&
     NativeRedBox.dismiss != null
   ) {
diff --git a/React/Base/RCTConvert.h b/React/Base/RCTConvert.h
index 80001a94a7a4d7..c8ada90b6be305 100644
--- a/React/Base/RCTConvert.h
+++ b/React/Base/RCTConvert.h
@@ -101,6 +101,7 @@ typedef NSURL RCTFileURL;
 + (CGAffineTransform)CGAffineTransform:(id)json;
 
 + (RCTUIColor *)UIColor:(id)json; // TODO(OSS Candidate ISS#2710739)
++ (RCTUIColor *)NSColor:(id)json; // TODO(OSS Candidate ISS#2710739)
 + (CGColorRef)CGColor:(id)json CF_RETURNS_NOT_RETAINED;
 
 + (YGValue)YGValue:(id)json;
diff --git a/React/Base/RCTConvert.m b/React/Base/RCTConvert.m
index fe4f7689976fa7..b111ac512ed674 100644
--- a/React/Base/RCTConvert.m
+++ b/React/Base/RCTConvert.m
@@ -808,6 +808,11 @@ + (type)type:(id)json                                       \
   }
   return names;
 }
+
++ (RCTUIColor *)NSColor:(id)json
+{
+  return [RCTConvert UIColor:json];
+}
 // ]TODO(macOS ISS#2323203)
 
 + (RCTUIColor *)UIColor:(id)json // TODO(OSS Candidate ISS#2710739)
diff --git a/React/CxxBridge/RCTCxxBridge.mm b/React/CxxBridge/RCTCxxBridge.mm
index 6b912e8d78f043..48b1c970ac6788 100644
--- a/React/CxxBridge/RCTCxxBridge.mm
+++ b/React/CxxBridge/RCTCxxBridge.mm
@@ -26,6 +26,7 @@
 #import <React/RCTRedBox.h>
 #import <React/RCTUtils.h>
 #import <React/RCTFollyConvert.h>
+#import <React/RCTBundleURLProvider.h> // TODO(macOS ISS#2323203)
 #import <cxxreact/CxxNativeModule.h>
 #import <cxxreact/Instance.h>
 #import <cxxreact/JSBundleType.h>
@@ -929,7 +930,7 @@ - (void)executeSourceCode:(NSData *)sourceCode sync:(BOOL)sync
     BOOL isHotLoadingEnabled = devSettings.isHotLoadingEnabled;
     [self enqueueJSCall:@"HMRClient"
                  method:@"setup"
-                   args:@[@"ios", path, host, RCTNullIfNil(port), @(isHotLoadingEnabled)]
+                   args:@[kRCTPlatformName, path, host, RCTNullIfNil(port), @(isHotLoadingEnabled)] // TODO(macOS ISS#2323203)
              completion:NULL];
   }
 #endif
diff --git a/React/DevSupport/RCTPackagerConnection.mm b/React/DevSupport/RCTPackagerConnection.mm
index 3fb6714f756c79..3f9ba5e9c3e04d 100644
--- a/React/DevSupport/RCTPackagerConnection.mm
+++ b/React/DevSupport/RCTPackagerConnection.mm
@@ -87,7 +87,7 @@ - (instancetype)init
   components.scheme = @"http";
   components.port = @(kRCTBundleURLProviderDefaultPort);
   components.path = @"/message";
-  components.queryItems = @[[NSURLQueryItem queryItemWithName:@"role" value:@"ios"]];
+  components.queryItems = @[[NSURLQueryItem queryItemWithName:@"role" value:kRCTPlatformName]]; // TODO(macOS ISS#2323203)
   static dispatch_queue_t queue;
   static dispatch_once_t onceToken;
   dispatch_once(&onceToken, ^{