diff --git a/src/libslic3r/Feature/Interlocking/InterlockingGenerator.cpp b/src/libslic3r/Feature/Interlocking/InterlockingGenerator.cpp
index aa104801e4..b4e85bd9d2 100644
--- a/src/libslic3r/Feature/Interlocking/InterlockingGenerator.cpp
+++ b/src/libslic3r/Feature/Interlocking/InterlockingGenerator.cpp
@@ -243,7 +243,7 @@ std::vector<std::vector<ExPolygons>> InterlockingGenerator::generateMicrostructu
     cell_area_per_mesh_per_layer.resize(2);
     cell_area_per_mesh_per_layer[0].resize(2);
     const coord_t beam_w_sum = beam_width + beam_width;
-    const coord_t middle     = cell_size.x() * beam_width / beam_w_sum;
+    const coord_t middle     = coord_t(int64_t(cell_size.x()) * int64_t(beam_width) / beam_w_sum);
     const coord_t width[2]   = {middle, cell_size.x() - middle};
     for (size_t mesh_idx : {0ul, 1ul}) {
         Point offset(mesh_idx ? middle : 0, 0);