diff --git a/README.markdown b/README.markdown
index 5385e1122..3662860a2 100644
--- a/README.markdown
+++ b/README.markdown
@@ -131,9 +131,8 @@ The author is Alessandro Ranellucci.
         --infill-speed      Speed of print moves in mm/s (default: 60)
         --solid-infill-speed Speed of print moves for solid surfaces in mm/s (default: 60)
         --bridge-speed      Speed of bridge print moves in mm/s (default: 60)
-        --bottom-layer-speed-ratio
-                            Factor to increase/decrease speeds on bottom 
-                            layer by (default: 0.3)
+        --bottom-layer-speed Speed of print moves for bottom layer, expressed either as an absolute
+                            value or as a percentage over normal speeds (default: 30%)
         
       Accuracy options:
         --layer-height      Layer height in mm (default: 0.4)
diff --git a/lib/Slic3r.pm b/lib/Slic3r.pm
index 8839fb280..d5b32dc60 100644
--- a/lib/Slic3r.pm
+++ b/lib/Slic3r.pm
@@ -83,7 +83,7 @@ our $small_perimeter_speed  = 30;   # mm/s
 our $infill_speed           = 60;   # mm/s
 our $solid_infill_speed     = 60;   # mm/s
 our $bridge_speed           = 60;   # mm/s
-our $bottom_layer_speed_ratio   = 0.3;
+our $bottom_layer_speed     = '30%'; # mm/s or %  
 
 # acceleration options
 our $acceleration           = 0;
diff --git a/lib/Slic3r/Config.pm b/lib/Slic3r/Config.pm
index 25aa3b8f3..fbc3aa222 100644
--- a/lib/Slic3r/Config.pm
+++ b/lib/Slic3r/Config.pm
@@ -157,9 +157,9 @@ our $Options = {
         type    => 'f',
         aliases => [qw(bridge_feed_rate)],
     },
-    'bottom_layer_speed_ratio' => {
-        label   => 'Bottom layer speed ratio',
-        cli     => 'bottom-layer-speed-ratio=f',
+    'bottom_layer_speed' => {
+        label   => 'Bottom layer speed (mm/s or %)',
+        cli     => 'bottom-layer-speed=f',
         type    => 'f',
     },
     
diff --git a/lib/Slic3r/Extruder.pm b/lib/Slic3r/Extruder.pm
index d120a7401..78acd29ff 100644
--- a/lib/Slic3r/Extruder.pm
+++ b/lib/Slic3r/Extruder.pm
@@ -182,7 +182,11 @@ sub extrude_path {
     
     if ($Slic3r::cooling) {
         my $path_time = unscale($path_length) / $self->speeds->{$self->last_speed} * 60;
-        $path_time /= $Slic3r::bottom_layer_speed_ratio if $self->layer->id == 0;
+        if ($self->layer->id == 0) {
+            $path_time = $Slic3r::bottom_layer_speed =~ /^(\d+(?:\.\d+)?)%$/
+                ? $path_time / ($1/100)
+                : unscale($path_length) / $Slic3r::bottom_layer_speed * 60;
+        }
         $self->elapsed_time($self->elapsed_time + $path_time);
     }
     
@@ -318,11 +322,6 @@ sub _Gx {
     my ($gcode, $e, $comment) = @_;
     my $dec = $self->dec;
     
-    # apply the speed reduction for print moves on bottom layer
-    my $speed_multiplier = $e && $self->layer->id == 0 && $comment !~ /retract/
-        ? $Slic3r::bottom_layer_speed_ratio 
-        : 1;
-    
     # determine speed
     my $speed = ($e ? $self->speed : 'travel');
     
@@ -335,7 +334,15 @@ sub _Gx {
         } elsif ($self->last_speed eq 'bridge') {
             $append_bridge_off = 1;
         }
-        $gcode .= sprintf " F%.${dec}f", $self->speeds->{$speed} * $speed_multiplier;
+        
+        # apply the speed reduction for print moves on bottom layer
+        my $speed_f = $self->speeds->{$speed};
+        if ($e && $self->layer->id == 0 && $comment !~ /retract/) {
+            $speed_f = $Slic3r::bottom_layer_speed =~ /^(\d+(?:\.\d+)?)%$/
+                ? ($speed_f * $1/100)
+                : $Slic3r::bottom_layer_speed;
+        }
+        $gcode .= sprintf " F%.${dec}f", $speed_f;
         $self->last_speed($speed);
     }
     
diff --git a/lib/Slic3r/GUI/SkeinPanel.pm b/lib/Slic3r/GUI/SkeinPanel.pm
index 8e0c9887a..65c52732f 100644
--- a/lib/Slic3r/GUI/SkeinPanel.pm
+++ b/lib/Slic3r/GUI/SkeinPanel.pm
@@ -36,7 +36,7 @@ sub new {
         },
         speed => {
             title => 'Other speed settings',
-            options => [qw(travel_speed bottom_layer_speed_ratio)],
+            options => [qw(travel_speed bottom_layer_speed)],
         },
         accuracy => {
             title => 'Accuracy',
diff --git a/slic3r.pl b/slic3r.pl
index ce45e66c3..a1540ff82 100755
--- a/slic3r.pl
+++ b/slic3r.pl
@@ -175,9 +175,8 @@ $j
     --infill-speed      Speed of print moves in mm/s (default: $Slic3r::infill_speed)
     --solid-infill-speed Speed of print moves for solid surfaces in mm/s (default: $Slic3r::solid_infill_speed)
     --bridge-speed      Speed of bridge print moves in mm/s (default: $Slic3r::bridge_speed)
-    --bottom-layer-speed-ratio
-                        Factor to increase/decrease speeds on bottom 
-                        layer by (default: $Slic3r::bottom_layer_speed_ratio)
+    --bottom-layer-speed Speed of print moves for bottom layer, expressed either as an absolute
+                        value or as a percentage over normal speeds (default: $Slic3r::bottom_layer_speed)
     
   Accuracy options:
     --layer-height      Layer height in mm (default: $Slic3r::layer_height)