diff --git a/src/slic3r/GUI/PrintHostDialogs.cpp b/src/slic3r/GUI/PrintHostDialogs.cpp
index 6707dc0ed..bae60e47f 100644
--- a/src/slic3r/GUI/PrintHostDialogs.cpp
+++ b/src/slic3r/GUI/PrintHostDialogs.cpp
@@ -269,7 +269,7 @@ void PrintHostQueueDialog::on_error(Event &evt)
 
     set_state(evt.job_id, ST_ERROR);
 
-    auto errormsg = wxString::Format("%s\n%s", _(L("Error uploading to print host:")), evt.error);
+    auto errormsg = from_u8((boost::format("%1%\n%2%") % _utf8(L("Error uploading to print host:")) % std::string(evt.error.ToUTF8())).str());
     job_list->SetValue(wxVariant(0), evt.job_id, COL_PROGRESS);
     job_list->SetValue(wxVariant(errormsg), evt.job_id, COL_ERRORMSG);    // Stashes the error message into a hidden column for later
 
diff --git a/src/slic3r/GUI/Selection.cpp b/src/slic3r/GUI/Selection.cpp
index bb81b56c0..4707f0f06 100644
--- a/src/slic3r/GUI/Selection.cpp
+++ b/src/slic3r/GUI/Selection.cpp
@@ -1470,9 +1470,10 @@ void Selection::toggle_instance_printable_state()
             ModelInstance* instance = model_object->instances[instance_idx];
             const bool printable = !instance->printable;
 
-            wxString snapshot_text = model_object->instances.size() == 1 ? wxString::Format("%s %s",
-                                     printable ? _(L("Set Printable")) : _(L("Set Unprintable")), model_object->name) :
-                                     printable ? _(L("Set Printable Instance")) : _(L("Set Unprintable Instance"));
+            wxString snapshot_text = model_object->instances.size() == 1 ? wxString::FromUTF8((boost::format("%1% %2%")
+                                         % (printable ? _utf8(L("Set Printable")) : _utf8(L("Set Unprintable")))
+                                         % model_object->name).str()) :
+                                     (printable ? _(L("Set Printable Instance")) : _(L("Set Unprintable Instance")));
             wxGetApp().plater()->take_snapshot(snapshot_text);
 
             instance->printable = printable;
diff --git a/src/slic3r/GUI/Tab.cpp b/src/slic3r/GUI/Tab.cpp
index ac141caa4..1033ffac4 100644
--- a/src/slic3r/GUI/Tab.cpp
+++ b/src/slic3r/GUI/Tab.cpp
@@ -130,7 +130,7 @@ void Tab::create_preset_tab()
     add_scaled_button(panel, &m_btn_hide_incompatible_presets, m_bmp_hide_incompatible_presets.name());
 
     // TRN "Save current Settings"
-    m_btn_save_preset->SetToolTip(wxString::Format(_(L("Save current %s")),m_title));
+    m_btn_save_preset->SetToolTip(from_u8((boost::format(_utf8(L("Save current %s"))) % m_title).str()));
     m_btn_delete_preset->SetToolTip(_(L("Delete this preset")));
     m_btn_delete_preset->Disable();
 
@@ -956,8 +956,8 @@ void Tab::update_preset_description_line()
     } else if (parent == nullptr) {
         description_line = _(L("Current preset is inherited from the default preset."));
     } else {
-        description_line = wxString::Format(
-            _(L("Current preset is inherited from:\n\t%s")), GUI::from_u8(parent->name));
+        description_line = from_u8((boost::format(
+            _utf8(L("Current preset is inherited from:\n\t%s"))) % parent->name).str());
     }
 
     if (preset.is_default || preset.is_system)
@@ -1683,8 +1683,7 @@ void TabPrinter::build_printhost(ConfigOptionsGroup *optgroup)
         btn->Bind(wxEVT_BUTTON, [this](wxCommandEvent &e) {
             std::unique_ptr<PrintHost> host(PrintHost::get_print_host(m_config));
             if (! host) {
-                const auto text = wxString::Format("%s",
-                    _(L("Could not get a valid Printer Host reference")));
+                const wxString text = _(L("Could not get a valid Printer Host reference"));
                 show_error(this, text);
                 return;
             }
@@ -1753,11 +1752,11 @@ void TabPrinter::build_printhost(ConfigOptionsGroup *optgroup)
         line.full_width = 1;
 
         line.widget = [this, ca_file_hint] (wxWindow* parent) {
-            auto txt = new wxStaticText(parent, wxID_ANY, wxString::Format("%s\n\n\t%s",
-    wxString::Format(_(L("HTTPS CA File:\n\
+            auto txt = new wxStaticText(parent, wxID_ANY, from_u8((boost::format("%1%\n\n\t%2%")
+    % (boost::format(_utf8(L("HTTPS CA File:\n\
     \tOn this system, %s uses HTTPS certificates from the system Certificate Store or Keychain.\n\
-    \tTo use a custom CA file, please import your CA file into Certificate Store / Keychain.")), SLIC3R_APP_NAME),
-                ca_file_hint));
+    \tTo use a custom CA file, please import your CA file into Certificate Store / Keychain."))) % SLIC3R_APP_NAME).str()
+    % std::string(ca_file_hint.ToUTF8())).str()));
             txt->SetFont(Slic3r::GUI::wxGetApp().normal_font());
             auto sizer = new wxBoxSizer(wxHORIZONTAL);
             sizer->Add(txt);
@@ -2916,8 +2915,8 @@ bool Tab::may_discard_current_dirty_preset(PresetCollection* presets /*= nullptr
     std::string   type_name  = presets->name();
     wxString      tab        = "          ";
     wxString      name       = old_preset.is_default ?
-        wxString::Format(_(L("Default preset (%s)")), _(type_name)) :
-        wxString::Format(_(L("Preset (%s)")), _(type_name)) + "\n" + tab + old_preset.name;
+        from_u8((boost::format(_utf8(L("Default preset (%s)"))) % _utf8(type_name)).str()) :
+        from_u8((boost::format(_utf8(L("Preset (%s)"))) % _utf8(type_name)).str()) + "\n" + tab + old_preset.name;
 
     // Collect descriptions of the dirty options.
     wxString changes;
@@ -3173,7 +3172,7 @@ wxSizer* Tab::compatible_widget_create(wxWindow* parent, PresetDependencies &dep
 {
     deps.checkbox = new wxCheckBox(parent, wxID_ANY, _(L("All")));
     deps.checkbox->SetFont(Slic3r::GUI::wxGetApp().normal_font());
-    add_scaled_button(parent, &deps.btn, "printer_white", wxString::Format(" %s %s", _(L("Set")), dots), wxBU_LEFT | wxBU_EXACTFIT);
+    add_scaled_button(parent, &deps.btn, "printer_white", from_u8((boost::format(" %s %s") % _utf8(L("Set")) % std::string(dots.ToUTF8())).str()), wxBU_LEFT | wxBU_EXACTFIT);
     deps.btn->SetFont(Slic3r::GUI::wxGetApp().normal_font());
 
     auto sizer = new wxBoxSizer(wxHORIZONTAL);
@@ -3414,7 +3413,7 @@ ConfigOptionsGroupShp Page::new_optgroup(const wxString& title, int noncommon_la
 void SavePresetWindow::build(const wxString& title, const std::string& default_name, std::vector<std::string> &values)
 {
     // TRN Preset
-    auto text = new wxStaticText(this, wxID_ANY, wxString::Format(_(L("Save %s as:")), title),
+    auto text = new wxStaticText(this, wxID_ANY, from_u8((boost::format(_utf8(L("Save %s as:"))) % title).str()),
                                     wxDefaultPosition, wxDefaultSize);
     m_combo = new wxComboBox(this, wxID_ANY, from_u8(default_name),
                             wxDefaultPosition, wxDefaultSize, 0, 0, wxTE_PROCESS_ENTER);
diff --git a/src/slic3r/GUI/UpdateDialogs.cpp b/src/slic3r/GUI/UpdateDialogs.cpp
index 9619846da..b3b35d68d 100644
--- a/src/slic3r/GUI/UpdateDialogs.cpp
+++ b/src/slic3r/GUI/UpdateDialogs.cpp
@@ -265,8 +265,8 @@ MsgDataIncompatible::~MsgDataIncompatible() {}
 MsgDataLegacy::MsgDataLegacy() :
 	MsgDialog(nullptr, _(L("Configuration update")), _(L("Configuration update")))
 {
-	auto *text = new wxStaticText(this, wxID_ANY, wxString::Format(
-		_(L(
+    auto *text = new wxStaticText(this, wxID_ANY, from_u8((boost::format(
+        _utf8(L(
 			"%s now uses an updated configuration structure.\n\n"
 
 			"So called 'System presets' have been introduced, which hold the built-in default settings for various "
@@ -276,8 +276,9 @@ MsgDataLegacy::MsgDataLegacy() :
 
 			"Please proceed with the %s that follows to set up the new presets "
 			"and to choose whether to enable automatic preset updates."
-		)),
-        SLIC3R_APP_NAME, _(ConfigWizard::name())
+        )))
+        % SLIC3R_APP_NAME
+        % _utf8(ConfigWizard::name())).str()
 	));
 	text->Wrap(CONTENT_WIDTH * wxGetApp().em_unit());
 	content_sizer->Add(text);
diff --git a/src/slic3r/GUI/wxExtensions.cpp b/src/slic3r/GUI/wxExtensions.cpp
index d3d9e61a2..713cd187f 100644
--- a/src/slic3r/GUI/wxExtensions.cpp
+++ b/src/slic3r/GUI/wxExtensions.cpp
@@ -603,7 +603,9 @@ void apply_extruder_selector(wxBitmapComboBox** ctrl,
             ++i;
         }
 
-        (*ctrl)->Append(use_full_item_name ? wxString::Format("%s %d", str, i) : wxString::Format("%d", i), *bmp);
+        (*ctrl)->Append(use_full_item_name
+                        ? wxString::FromUTF8((boost::format("%1% %2%") % str % i).str())
+                        : wxString::Format("%d", i), *bmp);
         ++i;
     }
     (*ctrl)->SetSelection(0);
@@ -700,8 +702,9 @@ ModeButton::ModeButton( wxWindow*           parent,
 
 void ModeButton::Init(const wxString &mode)
 {
-    m_tt_focused = wxString::Format(_(L("Switch to the %s mode")), mode);
-    m_tt_selected = wxString::Format(_(L("Current mode is %s")), mode);
+    std::string mode_str = std::string(mode.ToUTF8());
+    m_tt_focused  = wxString::FromUTF8((boost::format(_utf8(L("Switch to the %s mode"))) % mode_str).str());
+    m_tt_selected = wxString::FromUTF8((boost::format(_utf8(L("Current mode is %s"))) % mode_str).str());
 
     SetBitmapMargins(3, 0);
 
diff --git a/src/slic3r/Utils/AstroBox.cpp b/src/slic3r/Utils/AstroBox.cpp
index 83a72e64a..20560f1c1 100644
--- a/src/slic3r/Utils/AstroBox.cpp
+++ b/src/slic3r/Utils/AstroBox.cpp
@@ -13,6 +13,7 @@
 
 #include "libslic3r/PrintConfig.hpp"
 #include "slic3r/GUI/I18N.hpp"
+#include "slic3r/GUI/GUI.hpp"
 #include "Http.hpp"
 
 
@@ -65,7 +66,7 @@ bool AstroBox::test(wxString &msg) const
                 const auto text = ptree.get_optional<std::string>("text");
                 res = validate_version_text(text);
                 if (! res) {
-                    msg = wxString::Format(_(L("Mismatched type of print host: %s")), text ? *text : "AstroBox");
+                    msg = GUI::from_u8((boost::format(_utf8(L("Mismatched type of print host: %s"))) % (text ? *text : "AstroBox")).str());
                 }
             }
             catch (const std::exception &) {
@@ -85,8 +86,10 @@ wxString AstroBox::get_test_ok_msg () const
 
 wxString AstroBox::get_test_failed_msg (wxString &msg) const
 {
-    return wxString::Format("%s: %s\n\n%s",
-        _(L("Could not connect to AstroBox")), msg, _(L("Note: AstroBox version at least 1.1.0 is required.")));
+    return GUI::from_u8((boost::format("%s: %s\n\n%s")
+        % _utf8(L("Could not connect to AstroBox"))
+        % std::string(msg.ToUTF8())
+        % _utf8(L("Note: AstroBox version at least 1.1.0 is required."))).str());
 }
 
 bool AstroBox::upload(PrintHostUpload upload_data, ProgressFn prorgess_fn, ErrorFn error_fn) const
diff --git a/src/slic3r/Utils/Duet.cpp b/src/slic3r/Utils/Duet.cpp
index 554d3f5f5..4536dd217 100644
--- a/src/slic3r/Utils/Duet.cpp
+++ b/src/slic3r/Utils/Duet.cpp
@@ -51,7 +51,9 @@ wxString Duet::get_test_ok_msg () const
 
 wxString Duet::get_test_failed_msg (wxString &msg) const
 {
-	return wxString::Format("%s: %s", _(L("Could not connect to Duet")), msg);
+    return GUI::from_u8((boost::format("%s: %s")
+                    % _utf8(L("Could not connect to Duet"))
+                    % std::string(msg.ToUTF8())).str());
 }
 
 bool Duet::upload(PrintHostUpload upload_data, ProgressFn prorgess_fn, ErrorFn error_fn) const
diff --git a/src/slic3r/Utils/FlashAir.cpp b/src/slic3r/Utils/FlashAir.cpp
index 735e4a70a..c033bd843 100644
--- a/src/slic3r/Utils/FlashAir.cpp
+++ b/src/slic3r/Utils/FlashAir.cpp
@@ -70,7 +70,10 @@ wxString FlashAir::get_test_ok_msg () const
 
 wxString FlashAir::get_test_failed_msg (wxString &msg) const
 {
-	return wxString::Format("%s: %s", _(L("Could not connect to FlashAir")), msg, _(L("Note: FlashAir with firmware 2.00.02 or newer and activated upload function is required.")));
+    return wxString::FromUTF8((boost::format("%s: %s")
+                    % _utf8(L("Could not connect to FlashAir"))
+                    % std::string(msg.ToUTF8())
+                    % _utf8(L("Note: FlashAir with firmware 2.00.02 or newer and activated upload function is required."))).str());
 }
 
 bool FlashAir::upload(PrintHostUpload upload_data, ProgressFn prorgess_fn, ErrorFn error_fn) const
diff --git a/src/slic3r/Utils/OctoPrint.cpp b/src/slic3r/Utils/OctoPrint.cpp
index 48f8ba0b9..ee87f822f 100644
--- a/src/slic3r/Utils/OctoPrint.cpp
+++ b/src/slic3r/Utils/OctoPrint.cpp
@@ -13,6 +13,7 @@
 
 #include "libslic3r/PrintConfig.hpp"
 #include "slic3r/GUI/I18N.hpp"
+#include "slic3r/GUI/GUI.hpp"
 #include "Http.hpp"
 
 
@@ -65,7 +66,7 @@ bool OctoPrint::test(wxString &msg) const
                 const auto text = ptree.get_optional<std::string>("text");
                 res = validate_version_text(text);
                 if (! res) {
-                    msg = wxString::Format(_(L("Mismatched type of print host: %s")), text ? *text : "OctoPrint");
+                    msg = GUI::from_u8((boost::format(_utf8(L("Mismatched type of print host: %s"))) % (text ? *text : "OctoPrint")).str());
                 }
             }
             catch (const std::exception &) {
@@ -85,8 +86,10 @@ wxString OctoPrint::get_test_ok_msg () const
 
 wxString OctoPrint::get_test_failed_msg (wxString &msg) const
 {
-    return wxString::Format("%s: %s\n\n%s",
-        _(L("Could not connect to OctoPrint")), msg, _(L("Note: OctoPrint version at least 1.1.0 is required.")));
+    return GUI::from_u8((boost::format("%s: %s\n\n%s")
+        % _utf8(L("Could not connect to OctoPrint"))
+        % std::string(msg.ToUTF8())
+        % _utf8(L("Note: OctoPrint version at least 1.1.0 is required."))).str());
 }
 
 bool OctoPrint::upload(PrintHostUpload upload_data, ProgressFn prorgess_fn, ErrorFn error_fn) const
@@ -178,7 +181,9 @@ wxString SL1Host::get_test_ok_msg () const
 
 wxString SL1Host::get_test_failed_msg (wxString &msg) const
 {
-    return wxString::Format("%s: %s", _(L("Could not connect to Prusa SLA")), msg);
+    return GUI::from_u8((boost::format("%s: %s")
+                    % _utf8(L("Could not connect to Prusa SLA"))
+                    % std::string(msg.ToUTF8())).str());
 }
 
 bool SL1Host::validate_version_text(const boost::optional<std::string> &version_text) const
diff --git a/src/slic3r/Utils/PresetUpdater.cpp b/src/slic3r/Utils/PresetUpdater.cpp
index 909595cc0..a28937e15 100644
--- a/src/slic3r/Utils/PresetUpdater.cpp
+++ b/src/slic3r/Utils/PresetUpdater.cpp
@@ -702,15 +702,15 @@ PresetUpdater::UpdateResult PresetUpdater::config_update(const Semver &old_slic3
 			const auto max_slic3r = incompat.version.max_slic3r_version;
 			wxString restrictions;
 			if (min_slic3r != Semver::zero() && max_slic3r != Semver::inf()) {
-				restrictions = wxString::Format(_(L("requires min. %s and max. %s")),
-					min_slic3r.to_string(),
-					max_slic3r.to_string()
+                restrictions = GUI::from_u8((boost::format(_utf8(L("requires min. %s and max. %s")))
+                    % min_slic3r.to_string()
+                    % max_slic3r.to_string()).str()
 				);
 			} else if (min_slic3r != Semver::zero()) {
-				restrictions = wxString::Format(_(L("requires min. %s")), min_slic3r.to_string());
+                restrictions = GUI::from_u8((boost::format(_utf8(L("requires min. %s"))) % min_slic3r.to_string()).str());
 				BOOST_LOG_TRIVIAL(debug) << "Bundle is not downgrade, user will now have to do whole wizard. This should not happen.";
 			} else {
-				restrictions = wxString::Format(_(L("requires max. %s")), max_slic3r.to_string());
+                restrictions = GUI::from_u8((boost::format(_utf8(L("requires max. %s"))) % max_slic3r.to_string()).str());
 			}
 
 			incompats_map.emplace(std::make_pair(incompat.vendor, std::move(restrictions)));