diff --git a/libs/kimath/src/geometry/shape_poly_set.cpp b/libs/kimath/src/geometry/shape_poly_set.cpp
index 0e6406dba9..50a6f8d0b5 100644
--- a/libs/kimath/src/geometry/shape_poly_set.cpp
+++ b/libs/kimath/src/geometry/shape_poly_set.cpp
@@ -1965,6 +1965,9 @@ static void partitionPolyIntoRegularCellGrid(
     {
         aOut.AddOutline( ps2.COutline( i ) );
     }
+
+    if( !aOut.OutlineCount() )
+        aOut = aPoly;
 }