diff --git a/src/m_misc.c b/src/m_misc.c
index 27a31099..1f8117be 100644
--- a/src/m_misc.c
+++ b/src/m_misc.c
@@ -291,7 +291,7 @@ char *M_DirName(const char *path)
 // allocated.
 const char *M_BaseName(const char *path)
 {
-    char *p;
+    const char *p;
 
     p = strrchr(path, DIR_SEPARATOR);
     if (p == NULL)
diff --git a/src/setup/execute.c b/src/setup/execute.c
index 7a3faa21..9293d5b0 100644
--- a/src/setup/execute.c
+++ b/src/setup/execute.c
@@ -54,9 +54,9 @@ struct execute_context_s
 // Returns the path to a temporary file of the given name, stored
 // inside the system temporary directory.
 
-static char *TempFile(char *s)
+static char *TempFile(const char *s)
 {
-    char *tempdir;
+    const char *tempdir;
 
 #ifdef _WIN32
     // Check the TEMP environment variable to find the location.
@@ -130,7 +130,7 @@ execute_context_t *NewExecuteContext(void)
     return result;
 }
 
-void AddCmdLineParameter(execute_context_t *context, char *s, ...)
+void AddCmdLineParameter(execute_context_t *context, const char *s, ...)
 {
     va_list args;
 
diff --git a/src/setup/execute.h b/src/setup/execute.h
index f3e90e3c..21530f14 100644
--- a/src/setup/execute.h
+++ b/src/setup/execute.h
@@ -28,7 +28,7 @@ typedef struct execute_context_s execute_context_t;
 #define IWAD_CHEX     (1 << 5)       /* chex.wad */
 
 execute_context_t *NewExecuteContext(void);
-void AddCmdLineParameter(execute_context_t *context, char *s, ...) PRINTF_ATTR(2, 3);
+void AddCmdLineParameter(execute_context_t *context, const char *s, ...) PRINTF_ATTR(2, 3);
 void PassThroughArguments(execute_context_t *context);
 int ExecuteDoom(execute_context_t *context);
 int FindInstalledIWADs(void);
diff --git a/src/setup/joystick.c b/src/setup/joystick.c
index b8600ef5..07388735 100644
--- a/src/setup/joystick.c
+++ b/src/setup/joystick.c
@@ -33,13 +33,13 @@
 
 typedef struct
 {
-    char *name;  // Config file name
+    const char *name;  // Config file name
     int value;
 } joystick_config_t;
 
 typedef struct
 {
-    char *name;
+    const char *name;
     int axes, buttons, hats;
     const joystick_config_t *configs;
 } known_joystick_t;
@@ -972,7 +972,7 @@ static void CalibrateJoystick(TXT_UNCAST_ARG(widget), TXT_UNCAST_ARG(unused))
 // GUI
 //
 
-static void AddJoystickControl(TXT_UNCAST_ARG(table), char *label, int *var)
+static void AddJoystickControl(TXT_UNCAST_ARG(table), const char *label, int *var)
 {
     TXT_CAST_ARG(txt_table_t, table);
     txt_joystick_input_t *joy_input;
diff --git a/src/setup/keyboard.c b/src/setup/keyboard.c
index b88fe92d..80a06278 100644
--- a/src/setup/keyboard.c
+++ b/src/setup/keyboard.c
@@ -146,7 +146,7 @@ static void KeySetCallback(TXT_UNCAST_ARG(widget), TXT_UNCAST_ARG(variable))
 
 // Add a label and keyboard input to the specified table.
 
-static void AddKeyControl(TXT_UNCAST_ARG(table), char *name, int *var)
+static void AddKeyControl(TXT_UNCAST_ARG(table), const char *name, int *var)
 {
     TXT_CAST_ARG(txt_table_t, table);
     txt_key_input_t *key_input;
@@ -158,7 +158,7 @@ static void AddKeyControl(TXT_UNCAST_ARG(table), char *name, int *var)
     TXT_SignalConnect(key_input, "set", KeySetCallback, var);
 }
 
-static void AddSectionLabel(TXT_UNCAST_ARG(table), char *title,
+static void AddSectionLabel(TXT_UNCAST_ARG(table), const char *title,
                             boolean add_space)
 {
     TXT_CAST_ARG(txt_table_t, table);
diff --git a/src/setup/mainmenu.c b/src/setup/mainmenu.c
index 62206b39..03116f62 100644
--- a/src/setup/mainmenu.c
+++ b/src/setup/mainmenu.c
@@ -181,7 +181,7 @@ static void LaunchDoom(void *unused1, void *unused2)
 
 static txt_button_t *GetLaunchButton(void)
 {
-    char *label;
+    const char *label;
 
     switch (gamemission)
     {
diff --git a/src/setup/mode.c b/src/setup/mode.c
index 15841530..dbe667df 100644
--- a/src/setup/mode.c
+++ b/src/setup/mode.c
@@ -44,13 +44,13 @@ static const iwad_t **iwads;
 
 typedef struct
 {
-    char *label;
+    const char *label;
     GameMission_t mission;
     int mask;
-    char *name;
-    char *config_file;
-    char *extra_config_file;
-    char *executable;
+    const char *name;
+    const char *config_file;
+    const char *extra_config_file;
+    const char *executable;
 } mission_config_t;
 
 // Default mission to fall back on, if no IWADs are found at all:
@@ -106,7 +106,7 @@ static int screenblocks = 9;
 static int detailLevel = 0;
 static char *savedir = NULL;
 static char *executable = NULL;
-static char *game_title = "Doom";
+static const char *game_title = "Doom";
 static char *back_flat = "F_PAVE01";
 static int comport = 0;
 static char *nickname = NULL;
@@ -367,12 +367,12 @@ void SetupMission(GameSelectCallback callback)
     }
 }
 
-char *GetExecutableName(void)
+const char *GetExecutableName(void)
 {
     return executable;
 }
 
-char *GetGameTitle(void)
+const char *GetGameTitle(void)
 {
     return game_title;
 }
diff --git a/src/setup/mode.h b/src/setup/mode.h
index 0ae8a2cb..2687a488 100644
--- a/src/setup/mode.h
+++ b/src/setup/mode.h
@@ -23,8 +23,8 @@ extern GameMission_t gamemission;
 
 void SetupMission(GameSelectCallback callback);
 void InitBindings(void);
-char *GetExecutableName(void);
-char *GetGameTitle(void);
+const char *GetExecutableName(void);
+const char *GetGameTitle(void);
 const iwad_t **GetIwads(void);
 
 #endif /* #ifndef SETUP_MODE_H */
diff --git a/src/setup/mouse.c b/src/setup/mouse.c
index 1c27d5a0..e25cd990 100644
--- a/src/setup/mouse.c
+++ b/src/setup/mouse.c
@@ -67,7 +67,7 @@ static void MouseSetCallback(TXT_UNCAST_ARG(widget), TXT_UNCAST_ARG(variable))
     }
 }
 
-static void AddMouseControl(TXT_UNCAST_ARG(table), char *label, int *var)
+static void AddMouseControl(TXT_UNCAST_ARG(table), const char *label, int *var)
 {
     TXT_CAST_ARG(txt_table_t, table);
     txt_mouse_input_t *mouse_input;
diff --git a/src/setup/multiplayer.c b/src/setup/multiplayer.c
index 809d70b2..3faaaca1 100644
--- a/src/setup/multiplayer.c
+++ b/src/setup/multiplayer.c
@@ -705,7 +705,7 @@ static txt_dropdown_list_t *GameTypeDropdown(void)
 // and the single player warp menu.  The parameters specify
 // the window title and whether to display multiplayer options.
 
-static void StartGameMenu(char *window_title, int multiplayer)
+static void StartGameMenu(const char *window_title, int multiplayer)
 {
     txt_window_t *window;
     txt_widget_t *iwad_selector;
@@ -984,7 +984,7 @@ static void QueryWindowClosed(TXT_UNCAST_ARG(window), void *unused)
     TXT_SetPeriodicCallback(NULL, NULL, 0);
 }
 
-static void ServerQueryWindow(char *title)
+static void ServerQueryWindow(const char *title)
 {
     txt_table_t *results_table;
 
@@ -1067,7 +1067,7 @@ void JoinMultiGame(TXT_UNCAST_ARG(widget), void *user_data)
 void SetChatMacroDefaults(void)
 {
     int i;
-    char *defaults[] = 
+    const char *const defaults[] =
     {
         HUSTR_CHATMACRO0,
         HUSTR_CHATMACRO1,
diff --git a/src/setup/txt_joyaxis.c b/src/setup/txt_joyaxis.c
index 498e5294..a863704d 100644
--- a/src/setup/txt_joyaxis.c
+++ b/src/setup/txt_joyaxis.c
@@ -32,7 +32,7 @@
 
 #define JOYSTICK_AXIS_WIDTH 20
 
-static char *CalibrationLabel(txt_joystick_axis_t *joystick_axis)
+static const char *CalibrationLabel(txt_joystick_axis_t *joystick_axis)
 {
     switch (joystick_axis->config_stage)
     {