diff --git a/.github/workflows/osrm-backend.yml b/.github/workflows/osrm-backend.yml
index 53a27b864..936093374 100644
--- a/.github/workflows/osrm-backend.yml
+++ b/.github/workflows/osrm-backend.yml
@@ -212,6 +212,17 @@ jobs:
             CXXCOMPILER: clang++-6.0
             ENABLE_CONAN: ON
 
+          - name: gcc-12-release
+            continue-on-error: false
+            node: 16
+            runs-on: ubuntu-22.04
+            BUILD_TOOLS: ON
+            BUILD_TYPE: Release
+            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
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)
         {