diff --git a/lib/Slic3r/GUI/MainFrame.pm b/lib/Slic3r/GUI/MainFrame.pm
index 69a63ed5d..eff8ae4b2 100644
--- a/lib/Slic3r/GUI/MainFrame.pm
+++ b/lib/Slic3r/GUI/MainFrame.pm
@@ -440,7 +440,7 @@ sub quick_slice {
         if ($params{reslice}) {
             $output_file = $qs_last_output_file if defined $qs_last_output_file;
         } elsif ($params{save_as}) {
-            $output_file = $sprint->expanded_output_filepath;
+            $output_file = $sprint->output_filepath;
             $output_file =~ s/\.gcode$/.svg/i if $params{export_svg};
             my $dlg = Wx::FileDialog->new($self, 'Save ' . ($params{export_svg} ? 'SVG' : 'G-code') . ' file as:',
                 wxTheApp->output_path(dirname($output_file)),
diff --git a/lib/Slic3r/GUI/Plater.pm b/lib/Slic3r/GUI/Plater.pm
index 967d0f1e9..a1ef237d4 100644
--- a/lib/Slic3r/GUI/Plater.pm
+++ b/lib/Slic3r/GUI/Plater.pm
@@ -1298,9 +1298,9 @@ sub export_gcode {
     
     # select output file
     if ($output_file) {
-        $self->{export_gcode_output_file} = $self->{print}->expanded_output_filepath($output_file);
+        $self->{export_gcode_output_file} = $self->{print}->output_filepath($output_file);
     } else {
-        my $default_output_file = $self->{print}->expanded_output_filepath($main::opt{output});
+        my $default_output_file = $self->{print}->output_filepath($main::opt{output});
         my $dlg = Wx::FileDialog->new($self, 'Save G-code file as:', wxTheApp->output_path(dirname($default_output_file)),
             basename($default_output_file), &Slic3r::GUI::FILE_WILDCARDS->{gcode}, wxFD_SAVE | wxFD_OVERWRITE_PROMPT);
         if ($dlg->ShowModal != wxID_OK) {
@@ -1571,7 +1571,7 @@ sub _get_export_file {
     
     my $output_file = $main::opt{output};
     {
-        $output_file = $self->{print}->expanded_output_filepath($output_file);
+        $output_file = $self->{print}->output_filepath($output_file);
         $output_file =~ s/\.gcode$/$suffix/i;
         my $dlg = Wx::FileDialog->new($self, "Save $format file as:", dirname($output_file),
             basename($output_file), &Slic3r::GUI::MODEL_WILDCARD, wxFD_SAVE | wxFD_OVERWRITE_PROMPT);
diff --git a/lib/Slic3r/Print.pm b/lib/Slic3r/Print.pm
index e18fa6abf..adef54113 100644
--- a/lib/Slic3r/Print.pm
+++ b/lib/Slic3r/Print.pm
@@ -77,7 +77,7 @@ sub export_gcode {
     $self->process;
     
     # output everything to a G-code file
-    my $output_file = $self->expanded_output_filepath($params{output_file});
+    my $output_file = $self->output_filepath($params{output_file} // '');
     $self->status_cb->(90, "Exporting G-code" . ($output_file ? " to $output_file" : ""));
     $self->write_gcode($params{output_fh} || $output_file);
     
@@ -105,7 +105,7 @@ sub export_svg {
     
     my $fh = $params{output_fh};
     if (!$fh) {
-        my $output_file = $self->expanded_output_filepath($params{output_file});
+        my $output_file = $self->output_filepath($params{output_file});
         $output_file =~ s/\.gcode$/.svg/i;
         Slic3r::open(\$fh, ">", $output_file) or die "Failed to open $output_file for writing\n";
         print "Exporting to $output_file..." unless $params{quiet};
@@ -326,45 +326,6 @@ sub write_gcode {
     }
 }
 
-# this method will return the supplied input file path after expanding its
-# format variables with their values
-sub expanded_output_filepath {
-    my $self = shift;
-    my ($path) = @_;
-    
-    return undef if !@{$self->objects};
-    my $input_file = first { defined $_ } map $_->model_object->input_file, @{$self->objects};
-    return undef if !defined $input_file;
-    
-    my $filename = my $filename_base = basename($input_file);
-    $filename_base =~ s/\.[^.]+$//;  # without suffix
-    
-    # set filename in placeholder parser so that it's available also in custom G-code
-    $self->placeholder_parser->set(input_filename => $filename);
-    $self->placeholder_parser->set(input_filename_base => $filename_base);
-    
-    # set other variables from model object
-    $self->placeholder_parser->set_multiple(
-        scale => [ map $_->model_object->instances->[0]->scaling_factor * 100 . "%", @{$self->objects} ],
-    );
-    
-    if ($path && -d $path) {
-        # if output path is an existing directory, we take that and append
-        # the specified filename format
-        $path = File::Spec->join($path, $self->config->output_filename_format);
-    } elsif (!$path) {
-        # if no explicit output file was defined, we take the input
-        # file directory and append the specified filename format
-        $path = (fileparse($input_file))[1] . $self->config->output_filename_format;
-    } else {
-        # path is a full path to a file so we use it as it is
-    }
-    
-    # make sure we use an up-to-date timestamp
-    $self->placeholder_parser->update_timestamp;
-    return $self->placeholder_parser->process($path);
-}
-
 # Wrapper around the C++ Slic3r::Print::validate()
 # to produce a Perl exception without a hang-up on some Strawberry perls.
 sub validate
diff --git a/lib/Slic3r/Print/Simple.pm b/lib/Slic3r/Print/Simple.pm
index 3771bfe4a..4fe3eb820 100644
--- a/lib/Slic3r/Print/Simple.pm
+++ b/lib/Slic3r/Print/Simple.pm
@@ -13,7 +13,7 @@ use Slic3r::Geometry qw(X Y);
 has '_print' => (
     is      => 'ro',
     default => sub { Slic3r::Print->new },
-    handles => [qw(apply_config extruders expanded_output_filepath
+    handles => [qw(apply_config extruders output_filepath
                     total_used_filament total_extruded_volume
                     placeholder_parser process)],
 );
diff --git a/t/custom_gcode.t b/t/custom_gcode.t
index 9d68d1eed..f6bfd366f 100644
--- a/t/custom_gcode.t
+++ b/t/custom_gcode.t
@@ -59,7 +59,7 @@ use Slic3r::Test;
     $config->set('start_gcode', "TRAVEL:[travel_speed] HEIGHT:[layer_height]\n");
     my $print = Slic3r::Test::init_print('20mm_cube', config => $config);
     
-    my $output_file = $print->print->expanded_output_filepath;
+    my $output_file = $print->print->output_filepath;
     my ($t, $h) = map $config->$_, qw(travel_speed layer_height);
     ok $output_file =~ /ts_${t}_/, 'print config options are replaced in output filename';
     ok $output_file =~ /lh_$h\./, 'region config options are replaced in output filename';
diff --git a/xs/src/libslic3r/Print.cpp b/xs/src/libslic3r/Print.cpp
index 434535ac9..4c14599c9 100644
--- a/xs/src/libslic3r/Print.cpp
+++ b/xs/src/libslic3r/Print.cpp
@@ -998,4 +998,34 @@ void Print::_make_skirt()
     this->skirt.reverse();
 }
 
+std::string
+Print::output_filename()
+{
+    this->placeholder_parser.update_timestamp();
+    return this->placeholder_parser.process(this->config.output_filename_format.value);
+}
+
+std::string
+Print::output_filepath(const std::string &path)
+{
+    // if we were supplied no path, generate an automatic one based on our first object's input file
+    if (path.empty()) {
+        // get the first input file name
+        std::string input_file;
+        FOREACH_OBJECT(this, object) {
+            input_file = (*object)->model_object()->input_file;
+            if (!input_file.empty()) break;
+        }
+        return (boost::filesystem::path(input_file).parent_path() / this->output_filename()).string();
+    }
+    
+    // if we were supplied a directory, use it and append our automatically generated filename
+    boost::filesystem::path p(path);
+    if (boost::filesystem::is_directory(p))
+        return (p / this->output_filename()).string();
+    
+    // if we were supplied a file which is not a directory, use it
+    return path;
+}
+
 }
diff --git a/xs/src/libslic3r/Print.hpp b/xs/src/libslic3r/Print.hpp
index f18432da6..233290854 100644
--- a/xs/src/libslic3r/Print.hpp
+++ b/xs/src/libslic3r/Print.hpp
@@ -253,6 +253,8 @@ class Print
     void auto_assign_extruders(ModelObject* model_object) const;
 
     void _make_skirt();
+    std::string output_filename();
+    std::string output_filepath(const std::string &path);
     
     private:
     void clear_regions();
diff --git a/xs/xsp/Print.xsp b/xs/xsp/Print.xsp
index 8651469cd..1931243e1 100644
--- a/xs/xsp/Print.xsp
+++ b/xs/xsp/Print.xsp
@@ -257,6 +257,8 @@ _constant()
     double max_allowed_layer_height() const;
     bool has_support_material() const;
     void auto_assign_extruders(ModelObject* model_object);
+    std::string output_filename();
+    std::string output_filepath(std::string path = "");
     
     void add_model_object(ModelObject* model_object, int idx = -1);
     bool apply_config(DynamicPrintConfig* config)