diff --git a/.github/workflows/osrm-backend.yml b/.github/workflows/osrm-backend.yml
index f2209ea0e..353f269ad 100644
--- a/.github/workflows/osrm-backend.yml
+++ b/.github/workflows/osrm-backend.yml
@@ -212,15 +212,26 @@ jobs:
           #   CXXCOMPILER: clang++-6.0
           #   ENABLE_CONAN: ON
 
-          # - name: gcc-11-release
+          # - name: gcc-12-release
           #   continue-on-error: false
           #   node: 16
-          #   runs-on: ubuntu-20.04
+          #   runs-on: ubuntu-22.04
           #   BUILD_TOOLS: ON
           #   BUILD_TYPE: Release
-          #   CCOMPILER: gcc-11
-          #   CXXCOMPILER: g++-11
+          #   CCOMPILER: gcc-12
+          #   CXXCOMPILER: g++-12
           #   ENABLE_BENCHMARKS: ON
+          #   CXXFLAGS: '-Wno-array-bounds -Wno-uninitialized'
+
+          - name: gcc-11-release
+            continue-on-error: false
+            node: 16
+            runs-on: ubuntu-20.04
+            BUILD_TOOLS: ON
+            BUILD_TYPE: Release
+            CCOMPILER: gcc-11
+            CXXCOMPILER: g++-11
+            ENABLE_BENCHMARKS: ON
 
           # - name: gcc-10-release
           #   continue-on-error: false
@@ -286,30 +297,30 @@ jobs:
           #   ENABLE_CONAN: ON
           #   NODE_PACKAGE_TESTS_ONLY: ON
 
-          # - name: conan-macos-x64-release-node
-          #   build_node_package: true
-          #   continue-on-error: true
-          #   node: 18
-          #   runs-on: macos-11
-          #   BUILD_TYPE: Release
-          #   CCOMPILER: clang
-          #   CXXCOMPILER: clang++
-          #   CUCUMBER_TIMEOUT: 60000
-          #   ENABLE_ASSERTIONS: ON
-          #   ENABLE_CONAN: ON
+          - name: conan-macos-x64-release-node
+            build_node_package: true
+            continue-on-error: true
+            node: 18
+            runs-on: macos-11
+            BUILD_TYPE: Release
+            CCOMPILER: clang
+            CXXCOMPILER: clang++
+            CUCUMBER_TIMEOUT: 60000
+            ENABLE_ASSERTIONS: ON
+            ENABLE_CONAN: ON
 
-          # - name: conan-macos-arm64-release-node
-          #   build_node_package: true
-          #   continue-on-error: true
-          #   node: 18
-          #   runs-on: macos-11
-          #   BUILD_TYPE: Release
-          #   CCOMPILER: clang
-          #   CXXCOMPILER: clang++
-          #   CUCUMBER_TIMEOUT: 60000
-          #   ENABLE_ASSERTIONS: ON
-          #   ENABLE_CONAN: ON
-          #   ENABLE_APPLE_SILICON: ON
+          - name: conan-macos-arm64-release-node
+            build_node_package: true
+            continue-on-error: true
+            node: 18
+            runs-on: macos-11
+            BUILD_TYPE: Release
+            CCOMPILER: clang
+            CXXCOMPILER: clang++
+            CUCUMBER_TIMEOUT: 60000
+            ENABLE_ASSERTIONS: ON
+            ENABLE_CONAN: ON
+            ENABLE_APPLE_SILICON: ON
 
     name: ${{ matrix.name}}
     continue-on-error: ${{ matrix.continue-on-error }}
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9f39ab328..d0b54e50c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,7 @@
 # Unreleased
   - Changes from 5.27.1
     - Build:
+      - ADDED: Add CI job which builds OSRM with gcc 12. [#6455](https://github.com/Project-OSRM/osrm-backend/pull/6455)
       - 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)
diff --git a/include/util/indexed_data.hpp b/include/util/indexed_data.hpp
index a0d97e443..712597784 100644
--- a/include/util/indexed_data.hpp
+++ b/include/util/indexed_data.hpp
@@ -216,7 +216,7 @@ template <int N, typename T = std::string> struct FixedGroupBlock
             std::numeric_limits<std::make_unsigned_t<ValueType>>::max();
 
         auto index = 0;
-        std::array<ValueType, BLOCK_SIZE> prefix;
+        std::array<ValueType, BLOCK_SIZE> prefix{};
 
         for (OffsetIterator curr = first, next = std::next(first); curr != last; ++curr, ++next)
         {