diff --git a/libcxx/cmake/caches/Generic-module-std-cxx26.cmake b/libcxx/cmake/caches/Generic-module-std-cxx26.cmake
new file mode 100644
--- /dev/null
+++ b/libcxx/cmake/caches/Generic-module-std-cxx26.cmake
@@ -0,0 +1,3 @@
+set(LIBCXX_ENABLE_STD_MODULES ON CACHE BOOL "")
+set(LIBCXX_TEST_PARAMS "enable_modules=std;std=c++26" CACHE STRING "")
+set(LIBCXXABI_TEST_PARAMS "std=c++26" CACHE STRING "")
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
@@ -146,8 +146,8 @@
           limit: 2
     timeout_in_minutes: 120
 
-  - label: "C++23 Module std"
-    command: "libcxx/utils/ci/run-buildbot generic-module-std-cxx23"
+  - label: "C++26 Module std"
+    command: "libcxx/utils/ci/run-buildbot generic-module-std-cxx26"
     artifact_paths:
       - "**/test-results.xml"
       - "**/*.abilist"
@@ -208,6 +208,27 @@
   #
   - wait
 
+  - label: "C++23 Module std"
+    command: "libcxx/utils/ci/run-buildbot generic-module-std-cxx23"
+    artifact_paths:
+      - "**/test-results.xml"
+      - "**/*.abilist"
+    env:
+        # Note modules require and absolute path for clang-scan-deps
+        # https://github.com/llvm/llvm-project/issues/61006
+        CC: "/usr/lib/llvm-${LLVM_HEAD_VERSION}/bin/clang"
+        CXX: "/usr/lib/llvm-${LLVM_HEAD_VERSION}/bin/clang++"
+        CMAKE: "/opt/bin/cmake"
+        ENABLE_CLANG_TIDY: "On"
+    agents:
+      queue: "libcxx-builders"
+      os: "linux"
+    retry:
+      automatic:
+        - exit_status: -1  # Agent was lost
+          limit: 2
+    timeout_in_minutes: 120
+
   - label: "C++23"
     command: "libcxx/utils/ci/run-buildbot generic-cxx23"
     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
@@ -419,6 +419,12 @@
     check-runtimes
     check-abi-list
 ;;
+generic-module-std-cxx26)
+    clean
+    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-module-std-cxx26.cmake"
+    check-runtimes
+    check-abi-list
+;;
 #
 # Parts removed
 #
diff --git a/libcxx/utils/libcxx/test/dsl.py b/libcxx/utils/libcxx/test/dsl.py
--- a/libcxx/utils/libcxx/test/dsl.py
+++ b/libcxx/utils/libcxx/test/dsl.py
@@ -443,11 +443,7 @@
 
     std = _getSubstitution('%{cxx_std}', config)
     if std == 'cxx26':
-        # This fails to work properly. It might be due to
-        #   CMAKE_CXX_STANDARD 26
-        # does not work in CMake 3.26, it requires the upcomming CMake 3.27.
-        # TODO MODULES test whether this is fixed with CMake 3.27.
-        std = '17'
+        std = '26'
     elif std == 'cxx23':
         std = '23'
     else: