diff --git a/.github/workflows/iwyu.yml b/.github/workflows/iwyu.yml
index 05d5643bdf7..3b972dca443 100644
--- a/.github/workflows/iwyu.yml
+++ b/.github/workflows/iwyu.yml
@@ -71,7 +71,7 @@ jobs:
       - name: Install missing software on Fedora
         if: contains(matrix.image, 'fedora')
         run: |
-          dnf install -y cmake clang pcre-devel
+          dnf install -y cmake clang
           dnf install -y libglvnd-devel  # fixes missing dependency for Qt in CMake
           dnf install -y p7zip-plugins  # required as fallback for py7zr in Qt installation
           dnf install -y python3-pip  # fixes missing pip module in jurplel/install-qt-action
@@ -125,7 +125,8 @@ jobs:
 
       - name: Prepare CMake
         run: |
-          cmake -S . -B cmake.output -Werror=dev -DCMAKE_BUILD_TYPE=Release -DHAVE_RULES=On -DBUILD_TESTING=On -DBUILD_GUI=On -DWITH_QCHART=On -DBUILD_TRIAGE=On -DENABLE_CHECK_INTERNAL=On -DCMAKE_GLOBAL_AUTOGEN_TARGET=On -DDISABLE_DMAKE=On -DCMAKE_DISABLE_PRECOMPILE_HEADERS=On -DCPPCHK_GLIBCXX_DEBUG=Off -DUSE_MATCHCOMPILER=Off -DEXTERNALS_AS_SYSTEM=On -DUSE_LIBCXX=${{ matrix.stdlib == 'libc++' }}
+          # TODO: re-enable HAVE_RULES
+          cmake -S . -B cmake.output -Werror=dev -DCMAKE_BUILD_TYPE=Release -DHAVE_RULES=Off -DBUILD_TESTING=On -DBUILD_GUI=On -DWITH_QCHART=On -DBUILD_TRIAGE=On -DENABLE_CHECK_INTERNAL=On -DCMAKE_GLOBAL_AUTOGEN_TARGET=On -DDISABLE_DMAKE=On -DCMAKE_DISABLE_PRECOMPILE_HEADERS=On -DCPPCHK_GLIBCXX_DEBUG=Off -DUSE_MATCHCOMPILER=Off -DEXTERNALS_AS_SYSTEM=On -DUSE_LIBCXX=${{ matrix.stdlib == 'libc++' }}
         env:
           CC: clang
           CXX: clang++
@@ -232,7 +233,8 @@ jobs:
 
       - name: Prepare CMake
         run: |
-          cmake -S . -B cmake.output -Werror=dev -DCMAKE_BUILD_TYPE=Release -DHAVE_RULES=On -DBUILD_TESTING=On -DBUILD_GUI=On -DWITH_QCHART=On -DBUILD_TRIAGE=On -DENABLE_CHECK_INTERNAL=On -DCMAKE_GLOBAL_AUTOGEN_TARGET=On -DDISABLE_DMAKE=On -DCMAKE_DISABLE_PRECOMPILE_HEADERS=On -DCPPCHK_GLIBCXX_DEBUG=Off -DUSE_MATCHCOMPILER=Off -DEXTERNALS_AS_SYSTEM=On -DUSE_LIBCXX=${{ matrix.use_libcxx }}
+          # TODO: re-enable HAVE_RULES
+          cmake -S . -B cmake.output -Werror=dev -DCMAKE_BUILD_TYPE=Release -DHAVE_RULES=Off -DBUILD_TESTING=On -DBUILD_GUI=On -DWITH_QCHART=On -DBUILD_TRIAGE=On -DENABLE_CHECK_INTERNAL=On -DCMAKE_GLOBAL_AUTOGEN_TARGET=On -DDISABLE_DMAKE=On -DCMAKE_DISABLE_PRECOMPILE_HEADERS=On -DCPPCHK_GLIBCXX_DEBUG=Off -DUSE_MATCHCOMPILER=Off -DEXTERNALS_AS_SYSTEM=On -DUSE_LIBCXX=${{ matrix.use_libcxx }}
         env:
           CC: clang-22
           CXX: clang++-22