diff --git a/lib/Slic3r/Extruder.pm b/lib/Slic3r/Extruder.pm
index d976e715..9f4cba2b 100644
--- a/lib/Slic3r/Extruder.pm
+++ b/lib/Slic3r/Extruder.pm
@@ -25,7 +25,11 @@ has '_mm3_per_mm_cache'         => (is => 'ro', default => sub {{}});
 
 sub _build_bridge_flow {
     my $self = shift;
-    return Slic3r::Flow::Bridge->new(nozzle_diameter => $self->nozzle_diameter);
+    
+    return Slic3r::Flow::Bridge->new(
+        nozzle_diameter     => $self->nozzle_diameter,
+        bridge_flow_ratio   => $self->config->bridge_flow_ratio,
+    );
 }
 
 sub _build_e_per_mm3 {
diff --git a/lib/Slic3r/Flow.pm b/lib/Slic3r/Flow.pm
index b4aaad49..a02f7b34 100644
--- a/lib/Slic3r/Flow.pm
+++ b/lib/Slic3r/Flow.pm
@@ -90,13 +90,14 @@ use Moo;
 extends 'Slic3r::Flow';
 
 # layer_height is not required in this case
-has '+layer_height' => (is => 'ro', required => 0);
+has '+layer_height'         => (is => 'ro', required => 0);
+has 'bridge_flow_ratio'     => (is => 'ro', required => 1);
 
 use Slic3r::Geometry qw(PI);
 
 sub _build_width {
     my $self = shift;
-    return sqrt($Slic3r::Config->bridge_flow_ratio * ($self->nozzle_diameter**2));
+    return sqrt($self->bridge_flow_ratio * ($self->nozzle_diameter**2));
 }
 
 sub _build_spacing {
diff --git a/lib/Slic3r/Print.pm b/lib/Slic3r/Print.pm
index 19ea2dce..83566b1f 100644
--- a/lib/Slic3r/Print.pm
+++ b/lib/Slic3r/Print.pm
@@ -39,9 +39,6 @@ sub BUILD {
 sub init_config {
     my $self = shift;
     
-    # store config in a handy place
-    $Slic3r::Config = $self->config;
-    
     # legacy with existing config files
     $self->config->set('first_layer_height', $self->config->layer_height)
         if !$self->config->first_layer_height;
@@ -861,7 +858,7 @@ sub write_gcode {
                 }
                 
                 my $buffer = Slic3r::GCode::CoolingBuffer->new(
-                    config      => $Slic3r::Config,
+                    config      => $self->config,
                     gcodegen    => $gcodegen,
                 );
                 
@@ -903,7 +900,7 @@ sub write_gcode {
         }
         
         my $buffer = Slic3r::GCode::CoolingBuffer->new(
-            config      => $Slic3r::Config,
+            config      => $self->config,
             gcodegen    => $gcodegen,
         );
         foreach my $print_z (sort { $a <=> $b } keys %layers) {
diff --git a/t/threads.t b/t/threads.t
index 420d58f3..106a68af 100644
--- a/t/threads.t
+++ b/t/threads.t
@@ -26,10 +26,10 @@ plan tests => 2;
     
 {
     my $thread = threads->create(sub {
-        # $print can't be inizialized outside the thread because Object->slice will
-        # modify it by removing meshes and popping layers
-        my $print = Slic3r::Test::init_print('20mm_cube');
-        Slic3r::Test::gcode($print);
+        {
+            my $print = Slic3r::Test::init_print('20mm_cube');
+            Slic3r::Test::gcode($print);
+        }
         Slic3r::thread_cleanup();
         return 1;
     });