diff --git a/MachO/Options.td b/MachO/Options.td
index 19f8509..11458d9 100644
--- a/MachO/Options.td
+++ b/MachO/Options.td
@@ -1413,3 +1413,9 @@
     HelpText<"Do not warn about issues that are only problems for binaries shipping to customers.">,
     Flags<[HelpHidden]>,
     Group<grp_ignored_silently>;
+
+// NOTE: This flag should be respected if -warn_duplicate_libraries is ever implemented.
+def no_warn_duplicate_libraries : Flag<["-"], "no_warn_duplicate_libraries">,
+    HelpText<"Do not warn if the input contains duplicate library options.">,
+    Flags<[HelpHidden]>,
+    Group<grp_ignored_silently>;
diff --git a/test/MachO/silent-ignore.s b/test/MachO/silent-ignore.s
index e57342c..58c3cc1 100644
--- a/test/MachO/silent-ignore.s
+++ b/test/MachO/silent-ignore.s
@@ -20,7 +20,7 @@
 
 ## Check that we don't emit any warnings nor errors for these unimplemented flags.
 # RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %s -o %t.o
-# RUN: %lld %t.o -o /dev/null -objc_abi_version 2 -debug_variant
+# RUN: %lld %t.o -o /dev/null -objc_abi_version 2 -debug_variant -no_warn_duplicate_libraries
 
 .globl _main
 _main: