diff --git a/Build.PL b/Build.PL
index b09e9e879..d7d4d8e8a 100644
--- a/Build.PL
+++ b/Build.PL
@@ -19,6 +19,7 @@ my $build = Module::Build->new(
         'Moo'                       => '0.091009',
         'perl'                      => '5.10.0',
         'Scalar::Util'              => '0',
+        'Storable'                  => '0',
         'Time::HiRes'               => '0',
     },
     build_requires => {
diff --git a/lib/Slic3r/GUI/Plater.pm b/lib/Slic3r/GUI/Plater.pm
index 36e0186e5..ae66ba8e7 100644
--- a/lib/Slic3r/GUI/Plater.pm
+++ b/lib/Slic3r/GUI/Plater.pm
@@ -692,6 +692,12 @@ sub make_model {
     my $model = Slic3r::Model->new;
     foreach my $plater_object (@{$self->{objects}}) {
         my $model_object = $plater_object->get_model_object;
+        
+        # if we need to alter the mesh, clone it first
+        if ($plater_object->scale != 1) {
+            $model_object = $model_object->clone;
+        }
+        
         my $new_model_object = $model->add_object(
             vertices    => $model_object->vertices,
             input_file  => $plater_object->input_file,
@@ -1091,7 +1097,7 @@ sub free_model_object {
     my $self = shift;
     
     # only delete mesh from memory if we can retrieve it from the original file
-    return unless $self->input_file && $self->input_file_object_id;
+    return unless $self->input_file && defined $self->input_file_object_id;
     $self->model_object(undef);
 }
 
diff --git a/lib/Slic3r/Model.pm b/lib/Slic3r/Model.pm
index fef1f8346..58473fa9f 100644
--- a/lib/Slic3r/Model.pm
+++ b/lib/Slic3r/Model.pm
@@ -75,6 +75,7 @@ use Moo;
 
 use List::Util qw(first);
 use Slic3r::Geometry qw(X Y Z);
+use Storable qw(dclone);
 
 has 'input_file' => (is => 'rw');
 has 'model'     => (is => 'ro', weak_ref => 1, required => 1);
@@ -145,6 +146,8 @@ sub check_manifoldness {
     return (first { !$_->mesh->check_manifoldness } @{$self->volumes}) ? 0 : 1;
 }
 
+sub clone { dclone($_[0]) }
+
 package Slic3r::Model::Volume;
 use Moo;