diff --git a/libcxx/utils/ci/buildkite-pipeline.yml b/libcxx/utils/ci/buildkite-pipeline.yml
--- a/libcxx/utils/ci/buildkite-pipeline.yml
+++ b/libcxx/utils/ci/buildkite-pipeline.yml
@@ -28,6 +28,17 @@
     soft_fail:
         - exit_status: 1
 
+  - label: "Feature-test macros"
+    command: "libcxx/utils/ci/run-buildbot check-feature-test-macros"
+    artifact_paths:
+      - "**/generate_feature_test_macro_components.patch"
+    agents:
+      queue: "libcxx-builders"
+    retry:
+      automatic:
+        - exit_status: -1  # Agent was lost
+          limit: 2
+
   - label: "C++03"
     command: "libcxx/utils/ci/run-buildbot generic-cxx03"
     artifact_paths:
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
@@ -132,6 +132,17 @@
     # Check if the diff is empty, fail otherwise.
     ! grep -q '^--- a' ${BUILD_DIR}/clang-format.patch
 ;;
+check-feature-test-macros)
+    clean
+    echo "+++ Checking output of utils/generate_feature_test_macro_components.py"
+    # We need to set --extensions so that clang-format checks extensionless files.
+    mkdir -p ${BUILD_DIR}
+	python3 libcxx/utils/generate_feature_test_macro_components.py
+	git diff \
+        | tee ${BUILD_DIR}/generate_feature_test_macro_components.patch
+    # Check if the diff is empty, fail otherwise.
+    ! grep -q '^--- a' ${BUILD_DIR}/generate_feature_test_macro_components.patch
+;;
 generic-cxx03)
     export CC=clang
     export CXX=clang++