diff --git a/lib/Slic3r/Print.pm b/lib/Slic3r/Print.pm
index bfa7c2c36e..444af35106 100644
--- a/lib/Slic3r/Print.pm
+++ b/lib/Slic3r/Print.pm
@@ -42,6 +42,14 @@ sub _trigger_config {
     # 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;
+    $self->config->set_ifndef('small_perimeter_speed',  $self->config->perimeter_speed);
+    $self->config->set_ifndef('bridge_speed',           $self->config->infill_speed);
+    $self->config->set_ifndef('solid_infill_speed',     $self->config->infill_speed);
+    $self->config->set_ifndef('top_solid_infill_speed', $self->config->solid_infill_speed);
+    
     # initialize extruder(s)
     $Slic3r::extruders = [];
     for my $t (0, map $_-1, map $self->config->get($_), qw(perimeter_extruder infill_extruder support_material_extruder)) {
@@ -71,12 +79,6 @@ sub _trigger_config {
     # G-code flavors
     $self->config->set('extrusion_axis', 'A') if $self->config->gcode_flavor eq 'mach3';
     $self->config->set('extrusion_axis', '')  if $self->config->gcode_flavor eq 'no-extrusion';
-    
-    # legacy with existing config files
-    $self->config->set_ifndef('small_perimeter_speed',  $self->config->perimeter_speed);
-    $self->config->set_ifndef('bridge_speed',           $self->config->infill_speed);
-    $self->config->set_ifndef('solid_infill_speed',     $self->config->infill_speed);
-    $self->config->set_ifndef('top_solid_infill_speed', $self->config->solid_infill_speed);
 }
 
 sub add_objects_from_file {