diff --git a/lib/Slic3r/GCode.pm b/lib/Slic3r/GCode.pm
index 27c1ccd35..cea5dcd54 100644
--- a/lib/Slic3r/GCode.pm
+++ b/lib/Slic3r/GCode.pm
@@ -90,7 +90,7 @@ sub change_layer {
     my $gcode = "";
     if (defined $self->layer_count) {
         # TODO: cap this to 99% and add an explicit M73 P100 in the end G-code
-        $gcode .= $self->writer->update_progress(int(99 * ($self->_layer_index / ($self->layer_count - 1))));
+        $gcode .= $self->writer->update_progress($self->_layer_index, $self->layer_count);
     }
     
     my $z = $layer->print_z + $self->config->z_offset;  # in unscaled coordinates
diff --git a/lib/Slic3r/GCode/Writer.pm b/lib/Slic3r/GCode/Writer.pm
index ed72cc2c2..1563ca7ac 100644
--- a/lib/Slic3r/GCode/Writer.pm
+++ b/lib/Slic3r/GCode/Writer.pm
@@ -129,11 +129,14 @@ sub set_acceleration {
 }
 
 sub update_progress {
-    my ($self, $percent) = @_;
+    my ($self, $num, $tot, $allow_100) = @_;
     
     return "" if $self->config->gcode_flavor !~ /^(?:makerware|sailfish)$/;
+    
+    my $percent = int($num/$tot*100);
+    $percent = min($percent, 99) if !$allow_100;
     return sprintf "M73 P%s%s\n",
-        int($percent),
+        $percent,
         $self->_comment('update progress');
 }
 
diff --git a/lib/Slic3r/Print.pm b/lib/Slic3r/Print.pm
index 68e6378f2..b814880b9 100644
--- a/lib/Slic3r/Print.pm
+++ b/lib/Slic3r/Print.pm
@@ -938,6 +938,7 @@ sub write_gcode {
     print $fh $gcodegen->retract;
     print $fh $gcodegen->writer->set_fan(0);
     printf $fh "%s\n", $gcodegen->placeholder_parser->process($self->config->end_gcode);
+    print $fh $gcodegen->writer->update_progress($gcodegen->layer_count, $gcodegen->layer_count, 1);  # 100%
     
     $self->total_used_filament(0);
     $self->total_extruded_volume(0);
diff --git a/t/gcode.t b/t/gcode.t
index f82bc72ac..ee92d199c 100644
--- a/t/gcode.t
+++ b/t/gcode.t
@@ -1,4 +1,4 @@
-use Test::More tests => 11;
+use Test::More tests => 16;
 use strict;
 use warnings;
 
@@ -101,15 +101,22 @@ use Slic3r::Test;
         my ($print, $comment) = @_;
         
         my @percent = ();
+        my $got_100 = 0;
+        my $extruding_after_100 = 0;
         Slic3r::GCode::Reader->new->parse(Slic3r::Test::gcode($print), sub {
             my ($self, $cmd, $args, $info) = @_;
         
             if ($cmd eq 'M73') {
                 push @percent, $args->{P};
+                $got_100 = 1 if $args->{P} eq '100';
+            }
+            if ($info->{extruding} && $got_100) {
+                $extruding_after_100 = 1;
             }
         });
         # the extruder heater is turned off when M73 P100 is reached
         ok !(defined first { $_ > 100 } @percent), "M73 is never given more than 100% ($comment)";
+        ok !$extruding_after_100, "no extrusions after M73 P100 ($comment)";
     };
     
     {
@@ -133,6 +140,13 @@ use Slic3r::Test;
         my $print = Slic3r::Test::init_print(['20mm_cube','20mm_cube'], config => $config);
         $test->($print, 'two objects');
     }
+    
+    {
+        my $config = Slic3r::Config->new_from_defaults;
+        $config->set('gcode_flavor', 'sailfish');
+        my $print = Slic3r::Test::init_print('20mm_cube', config => $config, scale_xyz => [1,1, 1/(20/$config->layer_height) ]);
+        $test->($print, 'one layer object');
+    }
 }
 
 __END__