diff --git a/audio/mididrv.cpp b/audio/mididrv.cpp
index 1cbe08b8549..e189d782967 100644
--- a/audio/mididrv.cpp
+++ b/audio/mididrv.cpp
@@ -173,7 +173,7 @@ Common::U32String MidiDriver::getDeviceString(DeviceHandle handle, DeviceStringT
 
 MidiDriver::DeviceHandle MidiDriver::detectDevice(int flags) {
 	// Query the selected music device (defaults to MT_AUTO device).
-	Common::String selDevStr = ConfMan.hasKey("music_driver") ? ConfMan.get("music_driver") : Common::String("auto");
+	Common::U32String selDevStr = ConfMan.hasKey("music_driver") ? ConfMan.get("music_driver") : Common::String("auto");
 	if ((flags & MDT_PREFER_FLUID) && selDevStr == "auto") {
 		selDevStr = "fluidsynth";
 	}
@@ -256,8 +256,8 @@ MidiDriver::DeviceHandle MidiDriver::detectDevice(int flags) {
 		// we display a warning and continue.
 		failedDevStr = selDevStr;
 		Common::U32String warningMsg = Common::String::format(
-			Common::convertFromU32String(_("The selected audio device '%s' was not found (e.g. might be turned off or disconnected).")).c_str(),
-			failedDevStr.c_str()) + " " + Common::convertFromU32String(_("Attempting to fall back to the next available device...")).c_str();
+			_("The selected audio device '%s' was not found (e.g. might be turned off or disconnected).").encode().c_str(),
+			failedDevStr.encode() + " " + _("Attempting to fall back to the next available device...").encode());
 		GUI::MessageDialog dialog(warningMsg);
 		dialog.runModal();
 	}
@@ -269,9 +269,9 @@ MidiDriver::DeviceHandle MidiDriver::detectDevice(int flags) {
 		} else {
 			// If the expressly selected device cannot be used we display a warning and continue.
 			failedDevStr = getDeviceString(hdl, MidiDriver::kDeviceName);
-			Common::String warningMsg = Common::String::format(
-				Common::convertFromU32String(_("The selected audio device '%s' cannot be used. See log file for more information.")).c_str(),
-				failedDevStr.c_str()) + " " + Common::convertFromU32String(_("Attempting to fall back to the next available device...")).c_str();
+			Common::U32String warningMsg = Common::String::format(
+				_("The selected audio device '%s' cannot be used. See log file for more information.").encode().c_str(),
+				failedDevStr.encode() + " " + _("Attempting to fall back to the next available device...").encode());
 			GUI::MessageDialog dialog(warningMsg);
 			dialog.runModal();
 		}
@@ -307,9 +307,9 @@ MidiDriver::DeviceHandle MidiDriver::detectDevice(int flags) {
 					// we display a warning and continue. Don't warn about the missing device if we did already (this becomes relevant if the
 					// missing device is selected as preferred device and also as GM or MT-32 device).
 					if (failedDevStr != devStr) {
-						Common::String warningMsg = Common::String::format(
-							Common::convertFromU32String(_("The preferred audio device '%s' was not found (e.g. might be turned off or disconnected).")).c_str(),
-							devStr.c_str()) + " " + Common::convertFromU32String(_("Attempting to fall back to the next available device...")).c_str();
+						Common::U32String warningMsg = Common::String::format(
+							_("The preferred audio device '%s' was not found (e.g. might be turned off or disconnected).").encode().c_str(),
+							devStr + " " + _("Attempting to fall back to the next available device...").encode());
 						GUI::MessageDialog dialog(warningMsg);
 						dialog.runModal();
 					}
@@ -324,9 +324,9 @@ MidiDriver::DeviceHandle MidiDriver::detectDevice(int flags) {
 						// Don't warn about the failing device if we did already (this becomes relevant if the failing
 						// device is selected as preferred device and also as GM or MT-32 device).
 						if (failedDevStr != getDeviceString(hdl, MidiDriver::kDeviceName)) {
-							Common::String warningMsg = Common::String::format(
-								Common::convertFromU32String(_("The preferred audio device '%s' cannot be used. See log file for more information.")).c_str(),
-								getDeviceString(hdl, MidiDriver::kDeviceName).c_str()) + " " + Common::convertFromU32String(_("Attempting to fall back to the next available device...")).c_str();
+							Common::U32String warningMsg = Common::String::format(
+								_("The preferred audio device '%s' cannot be used. See log file for more information.").encode().c_str(),
+								getDeviceString(hdl, MidiDriver::kDeviceName).encode() + " " + _("Attempting to fall back to the next available device...").encode());
 							GUI::MessageDialog dialog(warningMsg);
 							dialog.runModal();
 						}
diff --git a/backends/cloud/storage.cpp b/backends/cloud/storage.cpp
index 90a554bf9d5..2569b38bf5b 100644
--- a/backends/cloud/storage.cpp
+++ b/backends/cloud/storage.cpp
@@ -346,7 +346,7 @@ void Storage::directoryDownloadedCallback(FileArrayResponse response) {
 	Common::U32String message;
 	if (response.value.size()) {
 		message = Common::String::format(
-			Common::convertFromU32String(_("Download complete.\nFailed to download %u files.")).c_str(),
+			_("Download complete.\nFailed to download %u files.").encode().c_str(),
 			response.value.size());
 	} else {
 		message = _("Download complete.");
diff --git a/backends/graphics/openglsdl/openglsdl-graphics.cpp b/backends/graphics/openglsdl/openglsdl-graphics.cpp
index ecf4ddb1825..1414fff63f2 100644
--- a/backends/graphics/openglsdl/openglsdl-graphics.cpp
+++ b/backends/graphics/openglsdl/openglsdl-graphics.cpp
@@ -583,7 +583,7 @@ bool OpenGLSdlGraphicsManager::notifyEvent(const Common::Event &event) {
 #ifdef USE_OSD
 		int windowWidth = 0, windowHeight = 0;
 		getWindowSizeFromSdl(&windowWidth, &windowHeight);
-		const Common::U32String osdMsg = Common::String::format(Common::convertFromU32String(_("Resolution: %dx%d")).c_str(), windowWidth, windowHeight);
+		const Common::U32String osdMsg = Common::String::format(_("Resolution: %dx%d").encode().c_str(), windowWidth, windowHeight);
 		displayMessageOnOSD(osdMsg);
 #endif
 
@@ -660,8 +660,8 @@ bool OpenGLSdlGraphicsManager::notifyEvent(const Common::Event &event) {
 
 #ifdef USE_OSD
 		Common::U32String message = Common::String::format("%s: %s",
-			_("Stretch mode"),
-			_(stretchModes[index].description)
+			_("Stretch mode").encode().c_str(),
+			_(stretchModes[index].description).encode().c_str()
 			);
 		displayMessageOnOSD(message);
 #endif
diff --git a/backends/graphics/surfacesdl/surfacesdl-graphics.cpp b/backends/graphics/surfacesdl/surfacesdl-graphics.cpp
index 0d9b3ef9c95..159c39912ff 100644
--- a/backends/graphics/surfacesdl/surfacesdl-graphics.cpp
+++ b/backends/graphics/surfacesdl/surfacesdl-graphics.cpp
@@ -2466,7 +2466,7 @@ void SurfaceSdlGraphicsManager::handleScalerHotkeys(int scalefactor, int scalerT
 		if (newScalerName) {
 			const Common::U32String message = Common::String::format(
 				"%s %s\n%d x %d -> %d x %d",
-				_("Active graphics filter:"),
+				_("Active graphics filter:").encode().c_str(),
 				newScalerName,
 				_videoMode.screenWidth, _videoMode.screenHeight,
 				_hwScreen->w, _hwScreen->h);
@@ -2500,13 +2500,13 @@ bool SurfaceSdlGraphicsManager::notifyEvent(const Common::Event &event) {
 		Common::U32String message;
 		if (_videoMode.aspectRatioCorrection)
 			message = Common::String::format("%s\n%d x %d -> %d x %d",
-			                                 _("Enabled aspect ratio correction"),
+			                                 _("Enabled aspect ratio correction").encode().c_str(),
 			                                 _videoMode.screenWidth, _videoMode.screenHeight,
 			                                 _hwScreen->w, _hwScreen->h
 			);
 		else
 			message = Common::String::format("%s\n%d x %d -> %d x %d",
-			                                 _("Disabled aspect ratio correction"),
+			                                 _("Disabled aspect ratio correction").encode().c_str(),
 			                                 _videoMode.screenWidth, _videoMode.screenHeight,
 			                                 _hwScreen->w, _hwScreen->h
 			);
@@ -2553,8 +2553,8 @@ bool SurfaceSdlGraphicsManager::notifyEvent(const Common::Event &event) {
 
 #ifdef USE_OSD
 		Common::U32String message = Common::String::format("%s: %s",
-		                                                _("Stretch mode"),
-		                                                _(s_supportedStretchModes[index].description)
+		                                                _("Stretch mode").encode().c_str(),
+		                                                _(s_supportedStretchModes[index].description).encode().c_str()
 		);
 		displayMessageOnOSD(message);
 #endif
diff --git a/backends/networking/sdl_net/handlers/filespagehandler.cpp b/backends/networking/sdl_net/handlers/filespagehandler.cpp
index fd5a37bcca3..b40dd1a53c4 100644
--- a/backends/networking/sdl_net/handlers/filespagehandler.cpp
+++ b/backends/networking/sdl_net/handlers/filespagehandler.cpp
@@ -229,7 +229,7 @@ void FilesPageHandler::handle(Client &client) {
 	replace(response, "{create_directory_desc}", _("Type new directory name:").encode());
 	replace(response, "{upload_file_desc}", _("Select a file to upload:").encode());
 	replace(response, "{or_upload_directory_desc}", _("Or select a directory (works in Chrome only):").encode());
-	replace(response, "{index_of_directory}", Common::String::format("%s %s", Common::convertFromU32String(_("Index of")).c_str(), encodeHtmlEntities(getDisplayPath(client.queryParameter("path"))).c_str()));
+	replace(response, "{index_of_directory}", Common::String::format("%s %s", _("Index of").encode().c_str(), encodeHtmlEntities(getDisplayPath(client.queryParameter("path")))));
 	replace(response, "{content}", content);
 	LocalWebserver::setClientGetHandler(client, response);
 }
diff --git a/common/achievements.cpp b/common/achievements.cpp
index 6f3cf6d3a06..7a7292522eb 100644
--- a/common/achievements.cpp
+++ b/common/achievements.cpp
@@ -89,7 +89,7 @@ bool AchievementsManager::setAchievement(const String &id, const String &display
 
 	if (!displayedMessage.empty() && g_system) {
 		U32String msg;
-		msg = Common::String::format("%s\n%s", _("Achievement unlocked!"), displayedMessage.c_str());
+		msg = Common::String::format("%s\n%s", _("Achievement unlocked!").encode().c_str(), displayedMessage.c_str());
 		g_system->displayMessageOnOSD(msg);
 	}
 
diff --git a/common/translation.cpp b/common/translation.cpp
index 7a8ad64e9b4..46d333e8c16 100644
--- a/common/translation.cpp
+++ b/common/translation.cpp
@@ -144,17 +144,17 @@ U32String TranslationManager::getTranslation(const char *message, const char *co
 			}
 			// Find the context we want
 			if (context == nullptr || *context == '\0' || leftIndex == rightIndex)
-				return _currentTranslationMessages[leftIndex].msgstr.c_str();
+				return _currentTranslationMessages[leftIndex].msgstr;
 			// We could use again binary search, but there should be only a small number of contexts.
 			while (rightIndex > leftIndex) {
 				compareResult = strcmp(context, _currentTranslationMessages[rightIndex].msgctxt.c_str());
 				if (compareResult == 0)
-					return _currentTranslationMessages[rightIndex].msgstr.c_str();
+					return _currentTranslationMessages[rightIndex].msgstr;
 				else if (compareResult > 0)
 					break;
 				--rightIndex;
 			}
-			return _currentTranslationMessages[leftIndex].msgstr.c_str();
+			return _currentTranslationMessages[leftIndex].msgstr;
 		} else if (compareResult < 0)
 			rightIndex = midIndex - 1;
 		else
diff --git a/gui/downloaddialog.cpp b/gui/downloaddialog.cpp
index 8edf0435a54..aeb4d927cd4 100644
--- a/gui/downloaddialog.cpp
+++ b/gui/downloaddialog.cpp
@@ -149,7 +149,7 @@ bool DownloadDialog::selectDirectories() {
 				return false;
 			}
 			GUI::MessageDialog alert(
-				Common::String::format(Common::convertFromU32String(_("The \"%s\" already exists in the specified directory.\nDo you really want to download files into that directory?")).c_str(), remoteDirectory.name().c_str()),
+				Common::String::format(_("The \"%s\" already exists in the specified directory.\nDo you really want to download files into that directory?").encode().c_str(), remoteDirectory.name().c_str()),
 				_("Yes"),
 				_("No")
 				);
@@ -212,14 +212,14 @@ Common::U32String DownloadDialog::getSizeLabelText() {
 	Common::String downloaded, downloadedUnits, total, totalUnits;
 	downloaded = getHumanReadableBytes(CloudMan.getDownloadBytesNumber(), downloadedUnits);
 	total = getHumanReadableBytes(CloudMan.getDownloadTotalBytesNumber(), totalUnits);
-	return Common::U32String::format(Common::convertFromU32String(_("Downloaded %s %s / %s %s")).c_str(), downloaded.c_str(), _(downloadedUnits.c_str()), total.c_str(), _(totalUnits.c_str()));
+	return Common::String::format(_("Downloaded %s %s / %s %s").encode().c_str(), downloaded.c_str(), _(downloadedUnits.c_str()).encode().c_str(), total.c_str(), _(totalUnits.c_str()).encode().c_str());
 }
 
 Common::U32String DownloadDialog::getSpeedLabelText() {
 	Common::String speed, speedUnits;
 	speed = getHumanReadableBytes(CloudMan.getDownloadSpeed(), speedUnits);
 	speedUnits += "/s";
-	return Common::U32String::format(_("Download speed: %s %s").encode().c_str(), speed.c_str(), _(speedUnits).encode().c_str());
+	return Common::String::format(_("Download speed: %s %s").encode().c_str(), speed.c_str(), _(speedUnits).encode().c_str());
 }
 
 void DownloadDialog::refreshWidgets() {
diff --git a/gui/massadd.cpp b/gui/massadd.cpp
index 64946119c2c..345db60cf91 100644
--- a/gui/massadd.cpp
+++ b/gui/massadd.cpp
@@ -266,14 +266,14 @@ void MassAddDialog::handleTickle() {
 		buf = _("Scan complete!");
 		_dirProgressText->setLabel(buf);
 
-		buf = Common::U32String::format(Common::convertFromU32String(_("Discovered %d new games, ignored %d previously added games.")).c_str(), _games.size(), _oldGamesCount);
+		buf = Common::String::format(Common::convertFromU32String(_("Discovered %d new games, ignored %d previously added games.")).c_str(), _games.size(), _oldGamesCount);
 		_gameProgressText->setLabel(buf);
 
 	} else {
-		buf = Common::U32String::format(Common::convertFromU32String(_("Scanned %d directories ...")).c_str(), _dirsScanned);
+		buf = Common::String::format(Common::convertFromU32String(_("Scanned %d directories ...")).c_str(), _dirsScanned);
 		_dirProgressText->setLabel(buf);
 
-		buf = Common::U32String::format(Common::convertFromU32String(_("Discovered %d new games, ignored %d previously added games ...")).c_str(), _games.size(), _oldGamesCount);
+		buf = Common::String::format(Common::convertFromU32String(_("Discovered %d new games, ignored %d previously added games ...")).c_str(), _games.size(), _oldGamesCount);
 		_gameProgressText->setLabel(buf);
 	}
 
diff --git a/gui/options.cpp b/gui/options.cpp
index ac88e8488b4..b58016957c2 100644
--- a/gui/options.cpp
+++ b/gui/options.cpp
@@ -1170,12 +1170,12 @@ void OptionsDialog::addAchievementsControls(GuiObject *boss, const Common::Strin
 	}
 
 	if (nHidden) {
-		Common::U32String hiddenStr = Common::U32String::format(Common::convertFromU32String(_("%d hidden achievements remaining")).c_str(), nHidden);
+		Common::U32String hiddenStr = Common::String::format(Common::convertFromU32String(_("%d hidden achievements remaining")).c_str(), nHidden);
 		new StaticTextWidget(scrollContainer, lineHeight, yPos, width, yStep, hiddenStr, Graphics::kTextAlignStart);
 	}
 
 	if (nMax) {
-		Common::U32String totalStr = Common::U32String::format(Common::convertFromU32String(_("Achievements unlocked: %d/%d")).c_str(), nAchieved, nMax);
+		Common::U32String totalStr = Common::String::format(Common::convertFromU32String(_("Achievements unlocked: %d/%d")).c_str(), nAchieved, nMax);
 		new StaticTextWidget(scrollContainer, lineHeight, lineHeight, width, yStep, totalStr, Graphics::kTextAlignStart);
 
 		SliderWidget *progressBar;
@@ -2148,7 +2148,7 @@ void GlobalOptionsDialog::addNetworkControls(GuiObject *boss, const Common::Stri
 	uint32 port = Networking::LocalWebserver::getPort();
 
 	_serverPortDesc = new StaticTextWidget(boss, prefix + "ServerPortDesc", (_("Server's port:")), _("Port for server to use"));
-	_serverPort = new EditTextWidget(boss, prefix + "ServerPortEditText", Common::U32String::format("%u", port), Common::U32String(""));
+	_serverPort = new EditTextWidget(boss, prefix + "ServerPortEditText", Common::String::format("%u", port), Common::U32String(""));
 	_serverPortClearButton = addClearButton(boss, prefix + "ServerPortClearButton", kServerPortClearCmd);
 
 	if (lowres) {
@@ -2805,7 +2805,7 @@ void GlobalOptionsDialog::setupCloudTab() {
 		uint64 usedSpace = CloudMan.getStorageUsedSpace(_selectedStorageIndex);
 		Common::String usedSpaceNumber, usedSpaceUnits;
 		usedSpaceNumber = Common::getHumanReadableBytes(usedSpace, usedSpaceUnits);
-		_storageUsedSpace->setLabel(Common::U32String::format("%s %s", usedSpaceNumber.c_str(), _(usedSpaceUnits.c_str()).encode().c_str()));
+		_storageUsedSpace->setLabel(Common::String::format("%s %s", usedSpaceNumber.c_str(), _(usedSpaceUnits.c_str()).encode().c_str()));
 		_storageUsedSpace->setVisible(shownConnectedInfo);
 	}
 	if (_storageSyncHint) {
diff --git a/gui/saveload-dialog.cpp b/gui/saveload-dialog.cpp
index 4aa051a6991..48369033f0c 100644
--- a/gui/saveload-dialog.cpp
+++ b/gui/saveload-dialog.cpp
@@ -1182,7 +1182,7 @@ void SavenameDialog::open() {
 	Dialog::open();
 	setResult(-1);
 
-	_title->setLabel(Common::U32String::format(Common::convertFromU32String(_("Enter a description for slot %d:")).c_str(), _targetSlot));
+	_title->setLabel(Common::String::format(Common::convertFromU32String(_("Enter a description for slot %d:")).c_str(), _targetSlot));
 }
 
 void SavenameDialog::handleCommand(CommandSender *sender, uint32 cmd, uint32 data) {