diff --git a/lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.cpp b/lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.cpp
--- a/lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.cpp
+++ b/lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.cpp
@@ -200,7 +200,7 @@
     specs.Append(module_spec);
     break;
   case MachineArm64:
-    spec.SetTriple("aarch64-unknown-windows");
+    spec.SetTriple("aarch64-pc-windows");
     specs.Append(module_spec);
     break;
   default:
diff --git a/lldb/test/Shell/ObjectFile/PECOFF/basic-info-arm64.yaml b/lldb/test/Shell/ObjectFile/PECOFF/basic-info-arm64.yaml
--- a/lldb/test/Shell/ObjectFile/PECOFF/basic-info-arm64.yaml
+++ b/lldb/test/Shell/ObjectFile/PECOFF/basic-info-arm64.yaml
@@ -2,7 +2,7 @@
 # RUN: lldb-test object-file %t | FileCheck %s
 
 # CHECK: Plugin name: pe-coff
-# CHECK: Architecture: aarch64-unknown-windows-msvc
+# CHECK: Architecture: aarch64-pc-windows-msvc
 # CHECK: UUID: 
 # CHECK: Executable: true
 # CHECK: Stripped: false