diff --git a/lib/Driver/ToolChains.cpp b/lib/Driver/ToolChains.cpp
index 7c849a364971d..2cde7c782a78e 100644
--- a/lib/Driver/ToolChains.cpp
+++ b/lib/Driver/ToolChains.cpp
@@ -204,6 +204,15 @@ void ToolChain::addCommonFrontendArgs(const OutputInfo &OI,
     arguments.push_back("-disable-objc-interop");
   }
 
+  if (Triple.isOSOpenBSD() && Triple.getArch() == llvm::Triple::aarch64) {
+    arguments.push_back("-Xcc");
+    arguments.push_back("-Xclang=-mbranch-target-enforce");
+    arguments.push_back("-Xcc");
+    arguments.push_back("-Xclang=-msign-return-address=non-leaf");
+    arguments.push_back("-Xcc");
+    arguments.push_back("-Xclang=-msign-return-address-key=a_key");
+  }
+
   if (inputArgs.getLastArg(options::OPT_experimental_serialize_debug_info)) {
     arguments.push_back(
         inputArgs.MakeArgString(Twine("-experimental-serialize-debug-info")));
diff --git a/utils/build-script-impl b/utils/build-script-impl
index 847fafb5a37f3..10598026149d7 100755
--- a/utils/build-script-impl
+++ b/utils/build-script-impl
@@ -1425,6 +1425,9 @@ function swift_c_flags() {
         linux-static-*)
             echo -n " -D_GNU_SOURCE -DHAVE_DECL_PROGRAM_INVOCATION_SHORT_NAME"
             ;;
+        openbsd-aarch64)
+            echo -n " -Xclang=-msign-return-address=non-leaf -Xclang=-msign-return-address-key=a_key -Xclang=-mbranch-target-enforce"
+            ;;
     esac
 }