diff --git a/.github/workflows/iwyu.yml b/.github/workflows/iwyu.yml
index 49d27809a89f..fe4243bdd488 100644
--- a/.github/workflows/iwyu.yml
+++ b/.github/workflows/iwyu.yml
@@ -16,6 +16,12 @@ jobs:
     strategy:
       matrix:
         image: ["fedora:latest"] # "opensuse/tumbleweed:latest" / "fedora:latest" / "debian:unstable" / "archlinux:latest"
+        use_libcxx: [Off, On]
+        include:
+          - use_libcxx: Off
+            stdlib: libstdc++
+          - use_libcxx: On
+            stdlib: libc++
 
     runs-on: ubuntu-22.04
     if: ${{ github.repository_owner == 'danmar' }}
@@ -87,7 +93,7 @@ jobs:
 
       - name: Prepare CMake
         run: |
-          cmake -S . -B cmake.output -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release -DHAVE_RULES=On -DBUILD_TESTS=On -DBUILD_GUI=On -DUSE_QT6=On -DWITH_QCHART=On -DENABLE_CHECK_INTERNAL=On -DCMAKE_GLOBAL_AUTOGEN_TARGET=On -DCMAKE_DISABLE_PRECOMPILE_HEADERS=On -DCPPCHK_GLIBCXX_DEBUG=Off -DUSE_MATCHCOMPILER=Off -DEXTERNALS_AS_SYSTEM=On
+          cmake -S . -B cmake.output -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release -DHAVE_RULES=On -DBUILD_TESTS=On -DBUILD_GUI=On -DUSE_QT6=On -DWITH_QCHART=On -DENABLE_CHECK_INTERNAL=On -DCMAKE_GLOBAL_AUTOGEN_TARGET=On -DCMAKE_DISABLE_PRECOMPILE_HEADERS=On -DCPPCHK_GLIBCXX_DEBUG=Off -DUSE_MATCHCOMPILER=Off -DEXTERNALS_AS_SYSTEM=On USE_LIBCXX=${{ matrix.use_libcxx }}
         env:
           CC: clang
           CXX: clang++
@@ -116,17 +122,26 @@ jobs:
       - uses: actions/upload-artifact@v4
         if: success() || failure()
         with:
-          name: Compilation Database
+          name: Compilation Database (${{ matrix.stdlib }})
           path: ./cmake.output/compile_commands.json
 
       - uses: actions/upload-artifact@v4
         if: success() || failure()
         with:
-          name: Logs (include-what-you-use)
+          name: Logs (include-what-you-use - ${{ matrix.stdlib }})
           path: ./*.log
 
   clang-include-cleaner:
 
+    strategy:
+      matrix:
+        use_libcxx: [Off, On]
+        include:
+          - use_libcxx: Off
+            stdlib: libstdc++
+          - use_libcxx: On
+            stdlib: libc++
+
     runs-on: ubuntu-22.04
     if: ${{ github.repository_owner == 'danmar' }}
 
@@ -160,7 +175,7 @@ jobs:
 
       - name: Prepare CMake
         run: |
-          cmake -S . -B cmake.output -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release -DHAVE_RULES=On -DBUILD_TESTS=On -DBUILD_GUI=On -DUSE_QT6=On -DWITH_QCHART=On -DENABLE_CHECK_INTERNAL=On -DCMAKE_GLOBAL_AUTOGEN_TARGET=On -DCMAKE_DISABLE_PRECOMPILE_HEADERS=On -DCPPCHK_GLIBCXX_DEBUG=Off -DUSE_MATCHCOMPILER=Off -DEXTERNALS_AS_SYSTEM=On
+          cmake -S . -B cmake.output -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release -DHAVE_RULES=On -DBUILD_TESTS=On -DBUILD_GUI=On -DUSE_QT6=On -DWITH_QCHART=On -DENABLE_CHECK_INTERNAL=On -DCMAKE_GLOBAL_AUTOGEN_TARGET=On -DCMAKE_DISABLE_PRECOMPILE_HEADERS=On -DCPPCHK_GLIBCXX_DEBUG=Off -DUSE_MATCHCOMPILER=Off -DEXTERNALS_AS_SYSTEM=On USE_LIBCXX=${{ matrix.use_libcxx }}
         env:
           CC: clang-19
           CXX: clang++-19
@@ -184,5 +199,5 @@ jobs:
 
       - uses: actions/upload-artifact@v4
         with:
-          name: Logs (clang-include-cleaner)
+          name: Logs (clang-include-cleaner - ${{ matrix.stdlib }})
           path: ./*.log