diff --git a/.clang-tidy b/.clang-tidy
index 1c87f8702..03f7f39d2 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -42,6 +42,7 @@ Checks: >
     -llvm-twine-local,
     misc-*,
     -misc-argument-comment,
+    -misc-const-correctness,
     -misc-non-private-member-variables-in-classes,
     -misc-unconventional-assign-operator,
     -misc-no-recursion,
diff --git a/.github/workflows/osrm-backend.yml b/.github/workflows/osrm-backend.yml
index e4d233a22..4edcaf771 100644
--- a/.github/workflows/osrm-backend.yml
+++ b/.github/workflows/osrm-backend.yml
@@ -180,14 +180,14 @@ jobs:
             CXXCOMPILER: clang++-6.0
             CUCUMBER_TIMEOUT: 60000
 
-          - name: clang-11.0-debug-clang-tidy
+          - name: clang-15.0-debug-clang-tidy
             continue-on-error: false
             node: 16
             runs-on: ubuntu-22.04
             BUILD_TOOLS: ON
             BUILD_TYPE: Debug
-            CCOMPILER: clang-14
-            CXXCOMPILER: clang++-14
+            CCOMPILER: clang-15
+            CXXCOMPILER: clang++-15
             CUCUMBER_TIMEOUT: 60000
             ENABLE_CLANG_TIDY: ON
 
@@ -488,10 +488,11 @@ jobs:
     - name: Install dev dependencies
       run: |
         python3 -m pip install conan==1.53.0
+
         # workaround for issue that GitHub Actions seems to not adding it to PATH after https://github.com/actions/runner-images/pull/6499
         # and that's why CI cannot find conan executable installed above
         if [[ "${RUNNER_OS}" == "macOS" ]]; then
-          echo "/Library/Frameworks/Python.framework/Versions/3.11/bin" >> $GITHUB_PATH
+          echo "/Library/Frameworks/Python.framework/Versions/Current/bin" >> $GITHUB_PATH
         fi
 
         # ccache
@@ -504,6 +505,12 @@ jobs:
         # clang
         if [[ "${CCOMPILER}" == "clang-6.0" ]]; then
           sudo apt-get update -y && sudo apt-get install clang++-6
+        elif [[ "${CCOMPILER}" == "clang-15" ]]; then
+          wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
+          sudo apt-get update -y && sudo apt-get install software-properties-common
+          sudo add-apt-repository 'deb http://apt.llvm.org/jammy/ llvm-toolchain-jammy-15 main'
+          sudo apt-get update -y && sudo apt-get install clang++-15 clang-tidy-15
+          sudo update-alternatives --install /usr/bin/clang-tidy clang-tidy /usr/bin/clang-tidy-15 100000
         fi
 
         # Linux dev packages
@@ -532,7 +539,6 @@ jobs:
         tar zxvf onetbb.tgz
         sudo cp -a oneapi-tbb-${TBB_VERSION}/lib/. /usr/local/lib/
         sudo cp -a oneapi-tbb-${TBB_VERSION}/include/. /usr/local/include/
-
     - name: Prepare build
       run: |
         mkdir ${OSRM_BUILD_DIR}
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 104145e68..253cad5c2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,7 @@
 # Unreleased
   - Changes from 5.27.1
     - Build:
+      - CHANGED: Upgrade to clang-tidy 15. [#6439](https://github.com/Project-OSRM/osrm-backend/pull/6439)
       - CHANGED: Update actions/cache to v3. [#6420](https://github.com/Project-OSRM/osrm-backend/pull/6420)
       - REMOVED: Drop support of Node 12 & 14. [#6431](https://github.com/Project-OSRM/osrm-backend/pull/6431)
     - Misc:
diff --git a/src/contractor/graph_contractor.cpp b/src/contractor/graph_contractor.cpp
index 9fb4749d3..07628523d 100644
--- a/src/contractor/graph_contractor.cpp
+++ b/src/contractor/graph_contractor.cpp
@@ -645,7 +645,6 @@ std::vector<bool> contractGraph(ContractorGraph &graph,
 
     const util::XORFastHash<> hash;
 
-    unsigned current_level = 0;
     std::size_t next_renumbering = number_of_nodes * 0.35;
     while (remaining_nodes.size() > number_of_core_nodes)
     {
@@ -761,7 +760,6 @@ std::vector<bool> contractGraph(ContractorGraph &graph,
         remaining_nodes.resize(begin_independent_nodes_idx);
 
         p.PrintStatus(number_of_contracted_nodes);
-        ++current_level;
     }
 
     node_data.Renumber(new_to_old_node_id);