diff --git a/src/libslic3r/PrintBase.cpp b/src/libslic3r/PrintBase.cpp
index 3fe9a2b4d..412aae338 100644
--- a/src/libslic3r/PrintBase.cpp
+++ b/src/libslic3r/PrintBase.cpp
@@ -57,8 +57,10 @@ std::string PrintBase::output_filename(const std::string &format, const std::str
     PlaceholderParser::update_timestamp(cfg);
     this->update_object_placeholders(cfg);
     try {
-        boost::filesystem::path filename = this->placeholder_parser().process(format, 0, &cfg);
-        if (filename.extension().empty())
+		boost::filesystem::path filename = format.empty() ?
+			cfg.opt_string("input_filename_base") + "." + default_ext :
+			this->placeholder_parser().process(format, 0, &cfg);
+		if (filename.extension().empty())
         	filename = boost::filesystem::change_extension(filename, default_ext);
         return filename.string();
     } catch (std::runtime_error &err) {
diff --git a/src/libslic3r/PrintConfig.cpp b/src/libslic3r/PrintConfig.cpp
index 8140177b3..3c8849d78 100644
--- a/src/libslic3r/PrintConfig.cpp
+++ b/src/libslic3r/PrintConfig.cpp
@@ -1323,7 +1323,7 @@ void PrintConfigDef::init_fff_params()
                    "[input_filename_base].");
     def->full_width = true;
     def->mode = comExpert;
-    def->set_default_value(new ConfigOptionString("[input_filename_base]"));
+    def->set_default_value(new ConfigOptionString("[input_filename_base].gcode"));
 
     def = this->add("overhangs", coBool);
     def->label = L("Detect bridging perimeters");
diff --git a/src/slic3r/GUI/PresetBundle.cpp b/src/slic3r/GUI/PresetBundle.cpp
index e92311cfe..f6cc73b6f 100644
--- a/src/slic3r/GUI/PresetBundle.cpp
+++ b/src/slic3r/GUI/PresetBundle.cpp
@@ -78,6 +78,7 @@ PresetBundle::PresetBundle() :
     this->sla_materials.default_preset().inherits();
 
     this->sla_prints.default_preset().config.optptr("sla_print_settings_id", true);
+    this->sla_prints.default_preset().config.opt_string("output_filename_format", true) = "[input_filename_base].sl1";
     this->sla_prints.default_preset().compatible_printers_condition();
     this->sla_prints.default_preset().inherits();