diff --git a/libcxx/utils/ci/run-buildbot b/libcxx/utils/ci/run-buildbot
--- a/libcxx/utils/ci/run-buildbot
+++ b/libcxx/utils/ci/run-buildbot
@@ -356,7 +356,8 @@
 ;;
 generic-no-unicode)
     clean
-    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-no-unicode.cmake"
+    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-no-unicode.cmake" \
+                   -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/llvm-libc++-shared.cfg.in"
     check-cxx-cxxabi
 ;;
 x86_64-apple-system)