diff --git a/src/libslic3r/GCode/SeamGeometry.cpp b/src/libslic3r/GCode/SeamGeometry.cpp
index f622d32e00..fbc4d07d93 100644
--- a/src/libslic3r/GCode/SeamGeometry.cpp
+++ b/src/libslic3r/GCode/SeamGeometry.cpp
@@ -215,7 +215,7 @@ BoundedPolygons project_to_geometry(const Geometry::Extrusions &external_perimet
             )};
 
             if (distance > max_bb_distance) {
-                Polygons expanded_extrusion{expand(external_perimeter.polygon, external_perimeter.width / 2.0)};
+                Polygons expanded_extrusion{expand(external_perimeter.polygon, Slic3r::scaled(external_perimeter.width / 2.0))};
                 if (!expanded_extrusion.empty()) {
                     return BoundedPolygon{
                         expanded_extrusion.front(), expanded_extrusion.front().bounding_box(), external_perimeter.polygon.is_clockwise(), 0.0
diff --git a/tests/fff_print/test_seam_shells.cpp b/tests/fff_print/test_seam_shells.cpp
index 56bd273780..852b17cbe4 100644
--- a/tests/fff_print/test_seam_shells.cpp
+++ b/tests/fff_print/test_seam_shells.cpp
@@ -52,7 +52,7 @@ TEST_CASE_METHOD(ProjectionFixture, "Project to geometry does not match", "[Seam
     REQUIRE(result.size() == 1);
     REQUIRE(result[0].polygon.size() == 4);
 
-    const Polygon expanded{expand(extrusions.front().polygon, extrusion_width / 2.0).front()};
+    const Polygon expanded{expand(extrusions.front().polygon, scaled(extrusion_width / 2.0)).front()};
 
     // The extrusion is expanded and returned.
     CHECK(result[0].polygon == expanded);