diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index bc585fc26e..d55a5ce26f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -334,6 +334,27 @@ jobs:
         CXX_STANDARD: '20'
       run: ./ci/do_ci.ps1 cmake.maintainer.cxx20.stl.test
 
+  cmake_msvc_maintainer_test_stl_cxx20_dll:
+    name: CMake msvc (maintainer mode) with C++20 (Build as DLL)
+    runs-on: windows-latest
+    steps:
+    - name: Harden the runner (Audit all outbound calls)
+      uses: step-security/harden-runner@0634a2670c59f64b4a01f0f96f84700a4088b9f0 # v2.12.0
+      with:
+        egress-policy: audit
+
+    - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      with:
+        submodules: 'recursive'
+    - name: setup
+      run: |
+        ./ci/setup_cmake.ps1
+        ./ci/setup_windows_ci_environment.ps1
+    - name: run tests (Build as DLL)
+      env:
+        CXX_STANDARD: '20'
+      run: ./ci/do_ci.ps1 cmake.maintainer.cxx20.stl.dll.test
+
   cmake_msvc_maintainer_abiv2_test:
     name: CMake msvc (maintainer mode, abiv2)
     runs-on: windows-latest
diff --git a/ci/do_ci.ps1 b/ci/do_ci.ps1
index 87aa73b6fa..e11f7af5c5 100644
--- a/ci/do_ci.ps1
+++ b/ci/do_ci.ps1
@@ -189,6 +189,32 @@ switch ($action) {
       exit $exit
     }
   }
+  "cmake.maintainer.cxx20.stl.dll.test" {
+    cd "$BUILD_DIR"
+    cmake $SRC_DIR `
+      -DOPENTELEMETRY_BUILD_DLL=1 `
+      -DWITH_STL=CXX20 `
+      -DCMAKE_CXX_STANDARD=20 `
+      -DWITH_OTLP_GRPC=ON `
+      -DWITH_OTLP_HTTP=ON `
+      -DWITH_OTLP_RETRY_PREVIEW=ON `
+      -DVCPKG_TARGET_TRIPLET=x64-windows `
+      "-DCMAKE_TOOLCHAIN_FILE=$VCPKG_DIR/scripts/buildsystems/vcpkg.cmake"
+    $exit = $LASTEXITCODE
+    if ($exit -ne 0) {
+      exit $exit
+    }
+    cmake --build . -j $nproc
+    $exit = $LASTEXITCODE
+    if ($exit -ne 0) {
+      exit $exit
+    }
+    ctest -C Debug
+    $exit = $LASTEXITCODE
+    if ($exit -ne 0) {
+      exit $exit
+    }
+  }
   "cmake.maintainer.abiv2.test" {
     cd "$BUILD_DIR"
     cmake $SRC_DIR `