diff --git a/lib/Slic3r/Print/Object.pm b/lib/Slic3r/Print/Object.pm
index d71ff140dc..9aa6ca7ec9 100644
--- a/lib/Slic3r/Print/Object.pm
+++ b/lib/Slic3r/Print/Object.pm
@@ -974,6 +974,7 @@ sub generate_support_material {
                 [
                     @{ $top{$z} || [] },
                 ],
+                1,
             );
         }
         
@@ -991,6 +992,7 @@ sub generate_support_material {
                     @{ $top{$z} || [] },
                     @{ $interface{$i} || [] },
                 ],
+                1,
             );
         }
     }