diff --git a/src/common/platform/posix/sdl/i_system.cpp b/src/common/platform/posix/sdl/i_system.cpp
index ab0c6bd7df8..183d11fc38b 100644
--- a/src/common/platform/posix/sdl/i_system.cpp
+++ b/src/common/platform/posix/sdl/i_system.cpp
@@ -118,7 +118,7 @@ void Unix_I_FatalError(const char* errortext)
 		FString cmd;
 		cmd << "kdialog --title \"" GAMENAME " " << GetVersionString()
 			<< "\" --msgbox \"" << errortext << "\"";
-		popen(cmd, "r");
+		popen(cmd.GetChars(), "r");
 	}
 #ifndef NO_GTK
 	else if (I_GtkAvailable())
@@ -131,7 +131,7 @@ void Unix_I_FatalError(const char* errortext)
 		FString title;
 		title << GAMENAME " " << GetVersionString();
 
-		if (SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR, title, errortext, NULL) < 0)
+		if (SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR, title.GetChars(), errortext, NULL) < 0)
 		{
 			printf("\n%s\n", errortext);
 		}
@@ -316,9 +316,9 @@ int I_PickIWad (WadStuff *wads, int numwads, bool showwin, int defaultiwad, int&
 
 		for(i = 0; i < numwads; ++i)
 		{
-			const char *filepart = strrchr(wads[i].Path, '/');
+			const char *filepart = strrchr(wads[i].Path.GetChars(), '/');
 			if(filepart == NULL)
-				filepart = wads[i].Path;
+				filepart = wads[i].Path.GetChars();
 			else
 				filepart++;
 			// Menu entries are specified in "tag" "item" pairs, where when a
@@ -329,9 +329,9 @@ int I_PickIWad (WadStuff *wads, int numwads, bool showwin, int defaultiwad, int&
 
 		if(defaultiwad >= 0 && defaultiwad < numwads)
 		{
-			const char *filepart = strrchr(wads[defaultiwad].Path, '/');
+			const char *filepart = strrchr(wads[defaultiwad].Path.GetChars(), '/');
 			if(filepart == NULL)
-				filepart = wads[defaultiwad].Path;
+				filepart = wads[defaultiwad].Path.GetChars();
 			else
 				filepart++;
 			cmd.AppendFormat(" --default \"%s (%s)\"", wads[defaultiwad].Name.GetChars(), filepart);
@@ -377,9 +377,9 @@ int I_PickIWad (WadStuff *wads, int numwads, bool showwin, int defaultiwad, int&
 	printf ("Please select a game wad (or 0 to exit):\n");
 	for (i = 0; i < numwads; ++i)
 	{
-		const char *filepart = strrchr (wads[i].Path, '/');
+		const char *filepart = strrchr (wads[i].Path.GetChars(), '/');
 		if (filepart == NULL)
-			filepart = wads[i].Path;
+			filepart = wads[i].Path.GetChars();
 		else
 			filepart++;
 		printf ("%d. %s (%s)\n", i+1, wads[i].Name.GetChars(), filepart);
diff --git a/src/common/platform/posix/sdl/sdlglvideo.cpp b/src/common/platform/posix/sdl/sdlglvideo.cpp
index 86a31c0c37d..edea37aa31d 100644
--- a/src/common/platform/posix/sdl/sdlglvideo.cpp
+++ b/src/common/platform/posix/sdl/sdlglvideo.cpp
@@ -139,7 +139,7 @@ namespace Priv
 		caption.Format(GAMENAME " %s (%s)", GetVersionString(), GetGitTime());
 
 		const uint32_t windowFlags = (win_maximized ? SDL_WINDOW_MAXIMIZED : 0) | SDL_WINDOW_RESIZABLE | extraFlags;
-		Priv::window = SDL_CreateWindow(caption,
+		Priv::window = SDL_CreateWindow(caption.GetChars(),
 			(win_x <= 0) ? SDL_WINDOWPOS_CENTERED_DISPLAY(vid_adapter) : win_x,
 			(win_y <= 0) ? SDL_WINDOWPOS_CENTERED_DISPLAY(vid_adapter) : win_y,
 			win_w, win_h, windowFlags);
@@ -585,7 +585,7 @@ void I_SetWindowTitle(const char* caption)
 	{
 		FString default_caption;
 		default_caption.Format(GAMENAME " %s (%s)", GetVersionString(), GetGitTime());
-		SDL_SetWindowTitle(Priv::window, default_caption);
+		SDL_SetWindowTitle(Priv::window, default_caption.GetChars());
 	}
 }
 
diff --git a/src/common/platform/posix/unix/i_specialpaths.cpp b/src/common/platform/posix/unix/i_specialpaths.cpp
index f844f0dd044..81cf2ae6693 100644
--- a/src/common/platform/posix/unix/i_specialpaths.cpp
+++ b/src/common/platform/posix/unix/i_specialpaths.cpp
@@ -50,15 +50,15 @@ FString GetUserFile (const char *file)
 
 	path = NicePath("$HOME/" GAME_DIR "/");
 
-	if (stat (path, &info) == -1)
+	if (stat (path.GetChars(), &info) == -1)
 	{
 		struct stat extrainfo;
 
 		// Sanity check for $HOME/.config
 		FString configPath = NicePath("$HOME/.config/");
-		if (stat (configPath, &extrainfo) == -1)
+		if (stat (configPath.GetChars(), &extrainfo) == -1)
 		{
-			if (mkdir (configPath, S_IRUSR | S_IWUSR | S_IXUSR) == -1)
+			if (mkdir (configPath.GetChars(), S_IRUSR | S_IWUSR | S_IXUSR) == -1)
 			{
 				I_FatalError ("Failed to create $HOME/.config directory:\n%s", strerror(errno));
 			}
@@ -72,9 +72,9 @@ FString GetUserFile (const char *file)
 		// Transfer the old zdoom directory to the new location
 		bool moved = false;
 		FString oldpath = NicePath("$HOME/." GAMENAMELOWERCASE "/");
-		if (stat (oldpath, &extrainfo) != -1)
+		if (stat (oldpath.GetChars(), &extrainfo) != -1)
 		{
-			if (rename(oldpath, path) == -1)
+			if (rename(oldpath.GetChars(), path) == -1)
 			{
 				I_Error ("Failed to move old " GAMENAMELOWERCASE " directory (%s) to new location (%s).",
 					oldpath.GetChars(), path.GetChars());
@@ -115,7 +115,7 @@ FString M_GetAppDataPath(bool create)
 	FString path = NicePath("$HOME/.config/" GAMENAMELOWERCASE);
 	if (create)
 	{
-		CreatePath(path);
+		CreatePath(path.GetChars());
 	}
 	return path;
 }
@@ -135,7 +135,7 @@ FString M_GetCachePath(bool create)
 	FString path = NicePath("$HOME/.config/zdoom/cache");
 	if (create)
 	{
-		CreatePath(path);
+		CreatePath(path.GetChars());
 	}
 	return path;
 }
@@ -231,7 +231,7 @@ FString M_GetDemoPath()
 FString M_GetNormalizedPath(const char* path)
 {
 	char *actualpath;
-	actualpath = realpath(path, NULL);
+	actualpath = realpath(path.GetChars(), NULL);
 	if (!actualpath) // error ?
 		return nullptr;
 	FString fullpath = actualpath;
diff --git a/src/ct_chat.cpp b/src/ct_chat.cpp
index acad5b35afc..ad4c99484ca 100644
--- a/src/ct_chat.cpp
+++ b/src/ct_chat.cpp
@@ -193,7 +193,7 @@ bool CT_Responder (event_t *ev)
 #ifdef __unix__
 		else if (ev->subtype == EV_GUI_MButtonDown)
 		{
-			CT_PasteChat(I_GetFromClipboard(true));
+			CT_PasteChat(I_GetFromClipboard(true).GetChars());
 		}
 #endif
 	}
diff --git a/src/d_main.cpp b/src/d_main.cpp
index 70c938ebf77..78421e707f6 100644
--- a/src/d_main.cpp
+++ b/src/d_main.cpp
@@ -2041,7 +2041,7 @@ static void AddAutoloadFiles(const char *autoname, std::vector<std::string>& all
 
 #ifdef __unix__
 		file = NicePath("$HOME/" GAME_DIR "/skins");
-		D_AddDirectory (allwads, file, "*.wad", GameConfig);
+		D_AddDirectory (allwads, file.GetChars(), "*.wad", GameConfig);
 #endif	
 
 		// Add common (global) wads
diff --git a/src/posix/i_steam.cpp b/src/posix/i_steam.cpp
index 913ae398912..046adca49ab 100644
--- a/src/posix/i_steam.cpp
+++ b/src/posix/i_steam.cpp
@@ -179,7 +179,7 @@ TArray<FString> I_GetSteamPath()
 	FString regPath = appSupportPath + "/Steam/config/config.vdf";
 	try
 	{
-		SteamInstallFolders = ParseSteamRegistry(regPath);
+		SteamInstallFolders = ParseSteamRegistry(regPath.GetChars());
 	}
 	catch(class CRecoverableError &error)
 	{