diff --git a/lib/Slic3r.pm b/lib/Slic3r.pm
index ca64d6216..12bdd2b9f 100644
--- a/lib/Slic3r.pm
+++ b/lib/Slic3r.pm
@@ -3,7 +3,7 @@ package Slic3r;
 use strict;
 use warnings;
 
-our $VERSION = "0.5.4";
+our $VERSION = "0.5.5beta";
 
 our $debug = 0;
 sub debugf {
diff --git a/lib/Slic3r/Config.pm b/lib/Slic3r/Config.pm
index e191f4d48..316405e27 100644
--- a/lib/Slic3r/Config.pm
+++ b/lib/Slic3r/Config.pm
@@ -12,6 +12,7 @@ our $Options = {
         label   => 'Nozzle diameter',
         cli     => 'nozzle-diameter=f',
         type    => 'f',
+        important => 1,
     },
     'print_center' => {
         label   => 'Print center',
@@ -27,7 +28,7 @@ our $Options = {
     },
     'extrusion_axis' => {
         label   => 'Extrusion axis',
-        cli     => 'extrusion_axis',
+        cli     => 'extrusion-axis',
         type    => 's',
     },
     'z_offset' => {
@@ -51,6 +52,7 @@ our $Options = {
         label   => 'Diameter (mm)',
         cli     => 'filament-diameter=f',
         type    => 'f',
+        important => 1,
     },
     'extrusion_multiplier' => {
         label   => 'Extrusion multiplier',
@@ -62,6 +64,7 @@ our $Options = {
         label   => 'Temperature (°C)',
         cli     => 'temperature=i',
         type    => 'i',
+        important => 1,
     },
     
     # speed options
diff --git a/lib/Slic3r/GUI/OptionsGroup.pm b/lib/Slic3r/GUI/OptionsGroup.pm
index 4b413d7fe..dbbcddef0 100644
--- a/lib/Slic3r/GUI/OptionsGroup.pm
+++ b/lib/Slic3r/GUI/OptionsGroup.pm
@@ -17,11 +17,14 @@ sub new {
     my $self = $class->SUPER::new($box, wxVERTICAL);
     
     my $grid_sizer = Wx::FlexGridSizer->new(scalar(@{$p{options}}), 2, 2, 0);
+    my $bold_font = Wx::SystemSettings::GetFont(0);
+    $bold_font->SetWeight(&Wx::wxFONTWEIGHT_BOLD);
     
     foreach my $opt_key (@{$p{options}}) {
         my $opt = $Slic3r::Config::Options->{$opt_key};
         my $label = Wx::StaticText->new($parent, -1, "$opt->{label}:", Wx::wxDefaultPosition, [180,-1]);
         $label->Wrap(180);  # needed to avoid Linux/GTK bug
+        $label->SetFont($bold_font) if $opt->{important};
         my $field;
         if ($opt->{type} =~ /^(i|f|s)$/) {
             my $style = 0;