diff --git a/lld/MachO/Driver.cpp b/lld/MachO/Driver.cpp
--- a/lld/MachO/Driver.cpp
+++ b/lld/MachO/Driver.cpp
@@ -766,6 +766,8 @@
   case OPT_grp_ignored:
     warn("Option `" + opt.getPrefixedName() + "' is ignored.");
     break;
+  case OPT_grp_ignored_silently:
+    break;
   default:
     warn("Option `" + opt.getPrefixedName() +
          "' is not yet implemented. Stay tuned...");
diff --git a/lld/MachO/Options.td b/lld/MachO/Options.td
--- a/lld/MachO/Options.td
+++ b/lld/MachO/Options.td
@@ -865,10 +865,6 @@
     HelpText<"Suppresses warnings about inputs whose architecture does not match the -arch option">,
     Flags<[HelpHidden]>,
     Group<grp_rare>;
-def arch_errors_fatal : Flag<["-"], "arch_errors_fatal">,
-    HelpText<"Escalate to errors any warnings about inputs whose architecture does not match the -arch option">,
-    Flags<[HelpHidden]>,
-    Group<grp_rare>;
 def e : Separate<["-"], "e">,
     MetaVarName<"<symbol>">,
     HelpText<"Make <symbol> the entry point of an executable (default is \"start\" from crt1.o)">,
@@ -1331,3 +1327,10 @@
     HelpText<"This option is ignored in ld64">,
     Flags<[HelpHidden]>,
     Group<grp_ignored>;
+
+def grp_ignored_silently : OptionGroup<"ignored_silently">, HelpText<"IGNORED SILENTLY">;
+
+def arch_errors_fatal : Flag<["-"], "arch_errors_fatal">,
+    HelpText<"Escalate to errors any warnings about inputs whose architecture does not match the -arch option, enabled by default">,
+    Flags<[HelpHidden]>,
+    Group<grp_ignored_silently>;
diff --git a/lld/test/MachO/invalid/incompatible-arch.s b/lld/test/MachO/invalid/incompatible-arch.s
--- a/lld/test/MachO/invalid/incompatible-arch.s
+++ b/lld/test/MachO/invalid/incompatible-arch.s
@@ -3,7 +3,9 @@
 # RUN: rm -rf %t && mkdir -p %t
 
 # RUN: llvm-mc -filetype=obj -triple=arm64-apple-darwin %s -o %t/test.o
+# RUN: %lld -arch arm64 -lSystem %t/test.o -o /dev/null -arch_errors_fatal
 # RUN: not %lld -arch x86_64 -lSystem %t/test.o -o /dev/null 2>&1 | FileCheck %s -DFILE=%t/test.o
+# RUN: not %lld -arch x86_64 -arch_errors_fatal -lSystem %t/test.o -o /dev/null 2>&1 | FileCheck %s -DFILE=%t/test.o
 # CHECK: error: {{.*}}[[FILE]] has architecture arm64 which is incompatible with target architecture x86_64
 
 # RUN: %lld -dylib -arch arm64 -platform_version macOS 10.14 10.15 -o %t/out.dylib %t/test.o