diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0bcf36c0af3..f12eac0a467 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@
       - FIXED: Fixed Boost link flags in pkg-config file. [#6083](https://github.com/Project-OSRM/osrm-backend/pull/6083)
     - Routing:
       - FIXED: Fix generation of inefficient MLD partitions [#6084](https://github.com/Project-OSRM/osrm-backend/pull/6084)
+      - FIXED: Fix metric offset overflow for large MLD partitions [#6124](https://github.com/Project-OSRM/osrm-backend/pull/6124)
 
 # 5.25.0
   - Changes from 5.24.0
diff --git a/include/partitioner/cell_storage.hpp b/include/partitioner/cell_storage.hpp
index 42c347861d2..3df8748262b 100644
--- a/include/partitioner/cell_storage.hpp
+++ b/include/partitioner/cell_storage.hpp
@@ -52,14 +52,13 @@ namespace detail
 template <storage::Ownership Ownership> class CellStorageImpl
 {
   public:
-    using ValueOffset = std::uint32_t;
-    using BoundaryOffset = std::uint32_t;
+    using ValueOffset = std::size_t;
+    using BoundaryOffset = std::size_t;
     using BoundarySize = std::uint32_t;
-    using SourceIndex = std::uint32_t;
-    using DestinationIndex = std::uint32_t;
 
     static constexpr auto INVALID_VALUE_OFFSET = std::numeric_limits<ValueOffset>::max();
     static constexpr auto INVALID_BOUNDARY_OFFSET = std::numeric_limits<BoundaryOffset>::max();
+    static constexpr auto MAX_BOUNDARY_SIZE = std::numeric_limits<BoundarySize>::max();
 
     struct CellData
     {
@@ -324,7 +323,10 @@ template <storage::Ownership Ownership> class CellStorageImpl
                 [this, insert_cell_boundary](auto begin, auto end) {
                     insert_cell_boundary(
                         source_boundary,
-                        [](auto &cell, auto value) { cell.num_source_nodes = value; },
+                        [](auto &cell, auto value) {
+                            BOOST_ASSERT(value < MAX_BOUNDARY_SIZE);
+                            cell.num_source_nodes = value;
+                        },
                         [](auto &cell, auto value) { cell.source_boundary_offset = value; },
                         begin,
                         end);
@@ -335,7 +337,10 @@ template <storage::Ownership Ownership> class CellStorageImpl
                 [this, insert_cell_boundary](auto begin, auto end) {
                     insert_cell_boundary(
                         destination_boundary,
-                        [](auto &cell, auto value) { cell.num_destination_nodes = value; },
+                        [](auto &cell, auto value) {
+                          BOOST_ASSERT(value < MAX_BOUNDARY_SIZE);
+                          cell.num_destination_nodes = value;
+                        },
                         [](auto &cell, auto value) { cell.destination_boundary_offset = value; },
                         begin,
                         end);