diff --git a/shell/platform/darwin/macos/framework/Source/FlutterEmbedderExternalTextureTest.mm b/shell/platform/darwin/macos/framework/Source/FlutterEmbedderExternalTextureTest.mm
index 75d1b16627fc8..1d0a6563c1b6f 100644
--- a/shell/platform/darwin/macos/framework/Source/FlutterEmbedderExternalTextureTest.mm
+++ b/shell/platform/darwin/macos/framework/Source/FlutterEmbedderExternalTextureTest.mm
@@ -59,7 +59,7 @@ - (CVPixelBufferRef)pixelBuffer {
   CVPixelBufferRef pxbuffer = NULL;
   CVReturn status = CVPixelBufferCreate(kCFAllocatorDefault, _width, _width, _pixelFormatType,
                                         (__bridge CFDictionaryRef)options, &pxbuffer);
-  NSAssert(status == kCVReturnSuccess && pxbuffer != NULL, @"Failed to create pixel buffer.");
+  FML_CHECK(status == kCVReturnSuccess && pxbuffer != nullptr) << "Failed to create pixel buffer";
   return pxbuffer;
 }
 
diff --git a/shell/platform/darwin/macos/framework/Source/FlutterEmbedderKeyResponder.mm b/shell/platform/darwin/macos/framework/Source/FlutterEmbedderKeyResponder.mm
index 37f67f94ee8f4..5feacb1d65272 100644
--- a/shell/platform/darwin/macos/framework/Source/FlutterEmbedderKeyResponder.mm
+++ b/shell/platform/darwin/macos/framework/Source/FlutterEmbedderKeyResponder.mm
@@ -167,9 +167,10 @@ static uint64_t GetLogicalKeyForEvent(NSEvent* event, uint64_t physicalKey) {
     uint32_t* keyLabel = DecodeUtf16(keyLabelUtf16, &keyLabelLength);
     if (keyLabelLength == 1) {
       uint32_t keyLabelChar = *keyLabel;
-      NSCAssert(!IsControlCharacter(keyLabelChar) && !IsUnprintableKey(keyLabelChar),
-                @"Unexpected control or unprintable keylabel 0x%x", keyLabelChar);
-      NSCAssert(keyLabelChar <= 0x10FFFF, @"Out of range keylabel 0x%x", keyLabelChar);
+      FML_DCHECK(!IsControlCharacter(keyLabelChar) && !IsUnprintableKey(keyLabelChar))
+          << "Unexpected control or unprintable keylabel 0x" << std::hex << keyLabelChar;
+      FML_DCHECK(keyLabelChar <= 0x10FFFF)
+          << "Out of range keylabel 0x" << std::hex << keyLabelChar;
       character = keyLabelChar;
     }
     delete[] keyLabel;