diff --git a/buildbot/osuosl/master/config/builders.py b/buildbot/osuosl/master/config/builders.py
--- a/buildbot/osuosl/master/config/builders.py
+++ b/buildbot/osuosl/master/config/builders.py
@@ -200,6 +200,7 @@
         {'name' : "llvm-clang-win-x-aarch64",
          'slavenames' : ["as-builder-2"],
          'builddir' : "clang-win-x-aarch64",
+         'slavebuilddir' : "x-aarch64",
          'mergeRequests': True,
          'factory': XToolchainBuilder.getCmakeWithMSVCBuildFactory(
                       vs="autodetect",