diff --git a/test/checkkeys.c b/test/checkkeys.c
index fc2767388..78b72651c 100644
--- a/test/checkkeys.c
+++ b/test/checkkeys.c
@@ -106,7 +106,7 @@ print_modifiers(char **text, size_t *maxlen)
 }
 
 static void
-PrintModifierState()
+PrintModifierState(void)
 {
     char message[512];
     char *spot;
@@ -165,7 +165,7 @@ PrintText(const char *eventtype, const char *text)
     SDL_Log("%s Text (%s): \"%s%s\"\n", eventtype, expanded, *text == '"' ? "\\" : "", text);
 }
 
-void loop()
+static void loop(void)
 {
     SDL_Event event;
     /* Check for events */
diff --git a/test/checkkeysthreads.c b/test/checkkeysthreads.c
index ca11ece8c..7ba3d8720 100644
--- a/test/checkkeysthreads.c
+++ b/test/checkkeysthreads.c
@@ -25,7 +25,7 @@
 #include <SDL3/SDL.h>
 #include <SDL3/SDL_main.h>
 
-int done;
+static int done;
 
 /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
 static void
@@ -103,7 +103,7 @@ print_modifiers(char **text, size_t *maxlen)
 }
 
 static void
-PrintModifierState()
+PrintModifierState(void)
 {
     char message[512];
     char *spot;
@@ -162,7 +162,7 @@ PrintText(const char *eventtype, const char *text)
     SDL_Log("%s Text (%s): \"%s%s\"\n", eventtype, expanded, *text == '"' ? "\\" : "", text);
 }
 
-void loop()
+static void loop(void)
 {
     SDL_Event event;
     /* Check for events */
diff --git a/test/gamepadmap.c b/test/gamepadmap.c
index 568fbcdfe..f41968da6 100644
--- a/test/gamepadmap.c
+++ b/test/gamepadmap.c
@@ -705,7 +705,7 @@ WatchJoystick(SDL_Joystick *joystick)
     SDL_DestroyRenderer(screen);
 }
 
-static SDL_bool HasJoysticks()
+static SDL_bool HasJoysticks(void)
 {
     int num_joysticks = 0;
     SDL_JoystickID *joysticks;
diff --git a/test/loopwave.c b/test/loopwave.c
index 38c6e30be..f4182fadb 100644
--- a/test/loopwave.c
+++ b/test/loopwave.c
@@ -44,7 +44,7 @@ quit(int rc)
 }
 
 static void
-close_audio()
+close_audio(void)
 {
     if (device != 0) {
         SDL_CloseAudioDevice(device);
@@ -53,7 +53,7 @@ close_audio()
 }
 
 static void
-open_audio()
+open_audio(void)
 {
     /* Initialize fillerup() variables */
     device = SDL_OpenAudioDevice(NULL, SDL_FALSE, &wave.spec, NULL, 0);
@@ -68,14 +68,14 @@ open_audio()
 }
 
 #ifndef __EMSCRIPTEN__
-static void reopen_audio()
+static void reopen_audio(void)
 {
     close_audio();
     open_audio();
 }
 #endif
 
-void SDLCALL
+static void SDLCALL
 fillerup(void *unused, Uint8 *stream, int len)
 {
     Uint8 *waveptr;
@@ -101,7 +101,7 @@ fillerup(void *unused, Uint8 *stream, int len)
 static int done = 0;
 
 #ifdef __EMSCRIPTEN__
-void loop()
+static void loop(void)
 {
     if (done || (SDL_GetAudioDeviceStatus(device) != SDL_AUDIO_PLAYING)) {
         emscripten_cancel_main_loop();
diff --git a/test/loopwavequeue.c b/test/loopwavequeue.c
index b56990fb9..0ecf5d296 100644
--- a/test/loopwavequeue.c
+++ b/test/loopwavequeue.c
@@ -43,14 +43,14 @@ quit(int rc)
 }
 
 static int done = 0;
-void poked(int sig)
+static void poked(int sig)
 {
     done = 1;
 }
 
 static SDL_AudioDeviceID g_audio_id = 0;
 
-void loop()
+static void loop(void)
 {
 #ifdef __EMSCRIPTEN__
     if (done || (SDL_GetAudioDeviceStatus(g_audio_id) != SDL_AUDIO_PLAYING)) {
diff --git a/test/testaudiohotplug.c b/test/testaudiohotplug.c
index 7e1fb5cf2..150e1f7eb 100644
--- a/test/testaudiohotplug.c
+++ b/test/testaudiohotplug.c
@@ -41,7 +41,7 @@ quit(int rc)
     exit(rc);
 }
 
-void SDLCALL
+static void SDLCALL
 fillerup(void *_pos, Uint8 *stream, int len)
 {
     Uint32 pos = *((Uint32 *)_pos);
@@ -67,19 +67,18 @@ fillerup(void *_pos, Uint8 *stream, int len)
 }
 
 static int done = 0;
-void poked(int sig)
+
+static void poked(int sig)
 {
     done = 1;
 }
 
-static const char *
-devtypestr(int iscapture)
+static const char *devtypestr(int iscapture)
 {
     return iscapture ? "capture" : "output";
 }
 
-static void
-iteration()
+static void iteration(void)
 {
     SDL_Event e;
     SDL_AudioDeviceID dev;
@@ -122,7 +121,7 @@ iteration()
 }
 
 #ifdef __EMSCRIPTEN__
-void loop()
+static void loop(void)
 {
     if (done)
         emscripten_cancel_main_loop();
diff --git a/test/testcustomcursor.c b/test/testcustomcursor.c
index 467c5fbe1..9438613a6 100644
--- a/test/testcustomcursor.c
+++ b/test/testcustomcursor.c
@@ -132,7 +132,7 @@ init_system_cursor(const char *image[])
 }
 
 static SDLTest_CommonState *state;
-int done;
+static int done;
 static SDL_Cursor *cursors[1 + SDL_NUM_SYSTEM_CURSORS];
 static SDL_SystemCursor cursor_types[1 + SDL_NUM_SYSTEM_CURSORS];
 static int num_cursors;
@@ -147,7 +147,7 @@ quit(int rc)
     exit(rc);
 }
 
-void loop()
+static void loop(void)
 {
     int i;
     SDL_Event event;
diff --git a/test/testdraw.c b/test/testdraw.c
index 844e07a67..833b1b5e7 100644
--- a/test/testdraw.c
+++ b/test/testdraw.c
@@ -36,9 +36,9 @@ static Uint64 next_fps_check;
 static Uint32 frames;
 static const int fps_check_delay = 5000;
 
-int done;
+static int done;
 
-void DrawPoints(SDL_Renderer *renderer)
+static void DrawPoints(SDL_Renderer *renderer)
 {
     int i;
     float x, y;
@@ -80,7 +80,7 @@ void DrawPoints(SDL_Renderer *renderer)
     }
 }
 
-void DrawLines(SDL_Renderer *renderer)
+static void DrawLines(SDL_Renderer *renderer)
 {
     int i;
     float x1, y1, x2, y2;
@@ -131,7 +131,7 @@ void DrawLines(SDL_Renderer *renderer)
     }
 }
 
-void DrawRects(SDL_Renderer *renderer)
+static void DrawRects(SDL_Renderer *renderer)
 {
     int i;
     SDL_FRect rect;
@@ -175,7 +175,7 @@ void DrawRects(SDL_Renderer *renderer)
     }
 }
 
-void loop()
+static void loop(void)
 {
     Uint64 now;
     int i;
diff --git a/test/testdrawchessboard.c b/test/testdrawchessboard.c
index 4bac05606..80b43197d 100644
--- a/test/testdrawchessboard.c
+++ b/test/testdrawchessboard.c
@@ -21,12 +21,13 @@
 #include <SDL3/SDL.h>
 #include <SDL3/SDL_main.h>
 
-SDL_Window *window;
-SDL_Renderer *renderer;
-SDL_Surface *surface;
-int done;
+static SDL_Window *window;
+static SDL_Renderer *renderer;
+static SDL_Surface *surface;
+static int done;
 
-void DrawChessBoard()
+
+static void DrawChessBoard(void)
 {
     int row = 0, column = 0, x = 0;
     SDL_FRect rect;
@@ -57,7 +58,7 @@ void DrawChessBoard()
     }
 }
 
-void loop()
+static void loop(void)
 {
     SDL_Event e;
     while (SDL_PollEvent(&e)) {
diff --git a/test/testgamepad.c b/test/testgamepad.c
index 7a3a6a852..247878b34 100644
--- a/test/testgamepad.c
+++ b/test/testgamepad.c
@@ -166,7 +166,7 @@ static void PrintJoystickInfo(SDL_JoystickID instance_id)
     }
 }
 
-static void UpdateWindowTitle()
+static void UpdateWindowTitle(void)
 {
     if (window == NULL) {
         return;
@@ -380,7 +380,7 @@ typedef struct
     Uint8 ucLedBlue;                  /* 46 */
 } DS5EffectsState_t;
 
-static void CyclePS5TriggerEffect()
+static void CyclePS5TriggerEffect(void)
 {
     DS5EffectsState_t state;
 
@@ -402,7 +402,7 @@ static void CyclePS5TriggerEffect()
     SDL_SendGamepadEffect(gamepad, &state, sizeof(state));
 }
 
-static SDL_bool ShowingFront()
+static SDL_bool ShowingFront(void)
 {
     SDL_bool showing_front = SDL_TRUE;
     int i;
@@ -445,7 +445,7 @@ static int SDLCALL VirtualGamepadSetLED(void *userdata, Uint8 red, Uint8 green,
     return 0;
 }
 
-static void OpenVirtualGamepad()
+static void OpenVirtualGamepad(void)
 {
     SDL_VirtualJoystickDesc desc;
     SDL_JoystickID virtual_id;
@@ -471,7 +471,7 @@ static void OpenVirtualGamepad()
     }
 }
 
-static void CloseVirtualGamepad()
+static void CloseVirtualGamepad(void)
 {
     int i;
     SDL_JoystickID *joysticks = SDL_GetJoysticks(NULL);
@@ -617,7 +617,7 @@ static void VirtualGamepadMouseUp(float x, float y)
     }
 }
 
-void loop(void *arg)
+static void loop(void *arg)
 {
     SDL_Event event;
     int i;
diff --git a/test/testgeometry.c b/test/testgeometry.c
index 9d0a2abe5..6f1b60b80 100644
--- a/test/testgeometry.c
+++ b/test/testgeometry.c
@@ -30,7 +30,7 @@ static SDL_BlendMode blendMode = SDL_BLENDMODE_NONE;
 static float angle = 0.0f;
 static int sprite_w, sprite_h;
 
-int done;
+static int done;
 
 /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
 static void
@@ -41,7 +41,7 @@ quit(int rc)
     exit(rc);
 }
 
-int LoadSprite(const char *file)
+static int LoadSprite(const char *file)
 {
     int i;
 
@@ -62,7 +62,7 @@ int LoadSprite(const char *file)
     return 0;
 }
 
-void loop()
+static void loop(void)
 {
     int i;
     SDL_Event event;
diff --git a/test/testgles2_sdf.c b/test/testgles2_sdf.c
index 56e1e803e..510140a85 100644
--- a/test/testgles2_sdf.c
+++ b/test/testgles2_sdf.c
@@ -35,9 +35,9 @@ typedef struct GLES2_Context
 } GLES2_Context;
 
 static SDL_Surface *g_surf_sdf = NULL;
-GLenum g_texture;
-GLenum g_texture_type = GL_TEXTURE_2D;
-GLfloat g_verts[24];
+static GLenum g_texture;
+static GLenum g_texture_type = GL_TEXTURE_2D;
+static GLfloat g_verts[24];
 typedef enum
 {
     GLES2_ATTRIBUTE_POSITION = 0,
@@ -53,7 +53,7 @@ typedef enum
     GLES2_UNIFORM_COLOR,
 } GLES2_Uniform;
 
-GLint g_uniform_locations[16];
+static GLint g_uniform_locations[16];
 
 static SDLTest_CommonState *state;
 static SDL_GLContext *context = NULL;
@@ -122,7 +122,7 @@ quit(int rc)
  * source: Passed-in shader source code.
  * shader_type: Passed to GL, e.g. GL_VERTEX_SHADER.
  */
-void process_shader(GLenum *shader, const char *source, GLenum shader_type)
+static void process_shader(GLenum *shader, const char *source, GLenum shader_type)
 {
     GLint status = GL_FALSE;
     const char *shaders[1] = { NULL };
@@ -266,7 +266,7 @@ Render(int width, int height, shader_data *data)
     GL_CHECK(ctx.glDrawArrays(GL_TRIANGLE_STRIP, 0, 4));
 }
 
-void renderCopy_angle(float degree_angle)
+static void renderCopy_angle(float degree_angle)
 {
     const float radian_angle = (float)(3.141592 * degree_angle) / 180.0f;
     const GLfloat s = (GLfloat)SDL_sin(radian_angle);
@@ -282,7 +282,7 @@ void renderCopy_angle(float degree_angle)
     *(verts++) = c;
 }
 
-void renderCopy_position(SDL_Rect *srcrect, SDL_Rect *dstrect)
+static void renderCopy_position(SDL_Rect *srcrect, SDL_Rect *dstrect)
 {
     GLfloat minx, miny, maxx, maxy;
     GLfloat minu, maxu, minv, maxv;
@@ -317,11 +317,11 @@ void renderCopy_position(SDL_Rect *srcrect, SDL_Rect *dstrect)
     *(verts++) = maxv;
 }
 
-int done;
-Uint32 frames;
-shader_data *datas;
+static int done;
+static Uint32 frames;
+static shader_data *datas;
 
-void loop()
+static void loop(void)
 {
     SDL_Event event;
     int i;
diff --git a/test/testintersections.c b/test/testintersections.c
index 2fa16bb3d..d5f53cb76 100644
--- a/test/testintersections.c
+++ b/test/testintersections.c
@@ -39,10 +39,10 @@ static int current_alpha = 255;
 static int current_color = 255;
 static SDL_BlendMode blendMode = SDL_BLENDMODE_NONE;
 
-float mouse_begin_x = -1.0f, mouse_begin_y = -1.0f;
-int done;
+static float mouse_begin_x = -1.0f, mouse_begin_y = -1.0f;
+static int done;
 
-void DrawPoints(SDL_Renderer *renderer)
+static void DrawPoints(SDL_Renderer *renderer)
 {
     int i;
     float x, y;
@@ -85,10 +85,9 @@ void DrawPoints(SDL_Renderer *renderer)
 }
 
 #define MAX_LINES 16
-int num_lines = 0;
-SDL_FRect lines[MAX_LINES];
-static int
-add_line(float x1, float y1, float x2, float y2)
+static int num_lines = 0;
+static SDL_FRect lines[MAX_LINES];
+static int add_line(float x1, float y1, float x2, float y2)
 {
     if (num_lines >= MAX_LINES) {
         return 0;
@@ -106,7 +105,7 @@ add_line(float x1, float y1, float x2, float y2)
     return ++num_lines;
 }
 
-void DrawLines(SDL_Renderer *renderer)
+static void DrawLines(SDL_Renderer *renderer)
 {
     int i;
     SDL_Rect viewport;
@@ -129,10 +128,9 @@ void DrawLines(SDL_Renderer *renderer)
 }
 
 #define MAX_RECTS 16
-int num_rects = 0;
-SDL_FRect rects[MAX_RECTS];
-static int
-add_rect(float x1, float y1, float x2, float y2)
+static int num_rects = 0;
+static SDL_FRect rects[MAX_RECTS];
+static int add_rect(float x1, float y1, float x2, float y2)
 {
     if (num_rects >= MAX_RECTS) {
         return 0;
@@ -208,7 +206,7 @@ DrawRectRectIntersections(SDL_Renderer *renderer)
     }
 }
 
-void loop()
+static void loop(void)
 {
     int i;
     SDL_Event event;
diff --git a/test/testjoystick.c b/test/testjoystick.c
index 057a6606c..f741c86af 100644
--- a/test/testjoystick.c
+++ b/test/testjoystick.c
@@ -99,7 +99,7 @@ DrawRect(SDL_Renderer *r, const int x, const int y, const int w, const int h)
     SDL_RenderFillRect(r, &area);
 }
 
-void loop(void *arg)
+static void loop(void *arg)
 {
     SDL_Event event;
     int i;
diff --git a/test/testmouse.c b/test/testmouse.c
index c6dc9c711..e0e3c70c0 100644
--- a/test/testmouse.c
+++ b/test/testmouse.c
@@ -51,7 +51,7 @@ static float wheel_y = SCREEN_HEIGHT * 0.5f;
 
 static SDL_bool done = SDL_FALSE;
 
-void DrawObject(SDL_Renderer *renderer, Object *object)
+static void DrawObject(SDL_Renderer *renderer, Object *object)
 {
     SDL_SetRenderDrawColor(renderer, object->r, object->g, object->b, 255);
 
@@ -80,7 +80,7 @@ void DrawObject(SDL_Renderer *renderer, Object *object)
     }
 }
 
-void DrawObjects(SDL_Renderer *renderer)
+static void DrawObjects(SDL_Renderer *renderer)
 {
     Object *next = objects;
     while (next != NULL) {
@@ -89,7 +89,7 @@ void DrawObjects(SDL_Renderer *renderer)
     }
 }
 
-void AppendObject(Object *object)
+static void AppendObject(Object *object)
 {
     if (objects) {
         Object *next = objects;
@@ -102,7 +102,7 @@ void AppendObject(Object *object)
     }
 }
 
-void loop(void *arg)
+static void loop(void *arg)
 {
     SDL_Renderer *renderer = (SDL_Renderer *)arg;
     SDL_Event event;
diff --git a/test/testmultiaudio.c b/test/testmultiaudio.c
index 45a5fec1b..a80c6e724 100644
--- a/test/testmultiaudio.c
+++ b/test/testmultiaudio.c
@@ -31,9 +31,9 @@ typedef struct
     SDL_atomic_t done;
 } callback_data;
 
-callback_data cbd[64];
+static callback_data cbd[64];
 
-void SDLCALL
+static void SDLCALL
 play_through_once(void *arg, Uint8 *stream, int len)
 {
     callback_data *cbdata = (callback_data *)arg;
@@ -54,18 +54,18 @@ play_through_once(void *arg, Uint8 *stream, int len)
     }
 }
 
-void loop()
+#ifdef __EMSCRIPTEN__
+static void loop(void)
 {
     if (SDL_AtomicGet(&cbd[0].done)) {
-#ifdef __EMSCRIPTEN__
         emscripten_cancel_main_loop();
-#endif
         SDL_PauseAudioDevice(cbd[0].dev);
         SDL_CloseAudioDevice(cbd[0].dev);
         SDL_free(sound);
         SDL_Quit();
     }
 }
+#endif
 
 static void
 test_multi_audio(int devcount)
diff --git a/test/testnative.c b/test/testnative.c
index 993cb7b7d..792327751 100644
--- a/test/testnative.c
+++ b/test/testnative.c
@@ -51,7 +51,7 @@ quit(int rc)
     exit(rc);
 }
 
-void MoveSprites(SDL_Renderer *renderer, SDL_Texture *sprite)
+static void MoveSprites(SDL_Renderer *renderer, SDL_Texture *sprite)
 {
     int sprite_w, sprite_h;
     int i;
diff --git a/test/testoffscreen.c b/test/testoffscreen.c
index f2ac3babd..78c1b382d 100644
--- a/test/testoffscreen.c
+++ b/test/testoffscreen.c
@@ -31,7 +31,7 @@ static int width = 640;
 static int height = 480;
 static unsigned int max_frames = 200;
 
-void draw()
+static void draw(void)
 {
     SDL_FRect rect;
 
@@ -49,7 +49,7 @@ void draw()
     SDL_RenderPresent(renderer);
 }
 
-void save_surface_to_bmp()
+static void save_surface_to_bmp(void)
 {
     SDL_Surface* surface;
     Uint32 pixel_format;
@@ -68,7 +68,7 @@ void save_surface_to_bmp()
     SDL_DestroySurface(surface);
 }
 
-void loop()
+static void loop(void)
 {
     SDL_Event event;
 
diff --git a/test/testoverlay.c b/test/testoverlay.c
index 39011934a..6b9adefa5 100644
--- a/test/testoverlay.c
+++ b/test/testoverlay.c
@@ -34,7 +34,7 @@
 #define MOOSEFRAMES_COUNT 10
 
 /* *INDENT-OFF* */ /* clang-format off */
-SDL_Color MooseColors[84] = {
+static SDL_Color MooseColors[84] = {
     {49, 49, 49, SDL_ALPHA_OPAQUE}
     , {66, 24, 0, SDL_ALPHA_OPAQUE}
     , {66, 33, 0, SDL_ALPHA_OPAQUE}
@@ -147,16 +147,16 @@ static Uint64 next_fps_check;
 static Uint32 frames;
 static const Uint32 fps_check_delay = 5000;
 
-SDL_Surface *MooseYUVSurfaces[MOOSEFRAMES_COUNT];
-SDL_Texture *MooseTexture = NULL;
-SDL_FRect displayrect;
-int window_w;
-int window_h;
-int paused = 0;
-int done = 0;
+static SDL_Surface *MooseYUVSurfaces[MOOSEFRAMES_COUNT];
+static SDL_Texture *MooseTexture = NULL;
+static SDL_FRect displayrect;
+static int window_w;
+static int window_h;
+static int paused = 0;
+static int done = 0;
 static int fpsdelay;
-SDL_bool streaming = SDL_TRUE;
-Uint8 *RawMooseData = NULL;
+static SDL_bool streaming = SDL_TRUE;
+static Uint8 *RawMooseData = NULL;
 
 /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
 static void
@@ -182,7 +182,7 @@ quit(int rc)
     }
 }
 
-void MoveSprites(SDL_Renderer *renderer)
+static void MoveSprites(SDL_Renderer *renderer)
 {
     static int i = 0;
 
@@ -216,7 +216,7 @@ void MoveSprites(SDL_Renderer *renderer)
 }
 
 
-void loop()
+static void loop(void)
 {
     Uint64 now;
     int i;
diff --git a/test/testrendercopyex.c b/test/testrendercopyex.c
index 408d7a2d1..9a3dc5bfc 100644
--- a/test/testrendercopyex.c
+++ b/test/testrendercopyex.c
@@ -33,8 +33,8 @@ typedef struct
     int scale_direction;
 } DrawState;
 
-DrawState *drawstates;
-int done;
+static DrawState *drawstates;
+static int done;
 
 /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
 static void
@@ -44,7 +44,7 @@ quit(int rc)
     exit(rc);
 }
 
-void Draw(DrawState *s)
+static void Draw(DrawState *s)
 {
     SDL_Rect viewport;
     SDL_Texture *target;
@@ -86,7 +86,7 @@ void Draw(DrawState *s)
     /* SDL_Delay(10); */
 }
 
-void loop()
+static void loop(void)
 {
     int i;
     SDL_Event event;
diff --git a/test/testrendertarget.c b/test/testrendertarget.c
index e1e0b7912..19b07fba2 100644
--- a/test/testrendertarget.c
+++ b/test/testrendertarget.c
@@ -33,9 +33,9 @@ typedef struct
     int scale_direction;
 } DrawState;
 
-DrawState *drawstates;
-int done;
-SDL_bool test_composite = SDL_FALSE;
+static DrawState *drawstates;
+static int done;
+static SDL_bool test_composite = SDL_FALSE;
 
 /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
 static void
@@ -45,7 +45,7 @@ quit(int rc)
     exit(rc);
 }
 
-SDL_bool
+static SDL_bool
 DrawComposite(DrawState *s)
 {
     SDL_Rect viewport;
@@ -129,7 +129,7 @@ DrawComposite(DrawState *s)
     return SDL_TRUE;
 }
 
-SDL_bool
+static SDL_bool
 Draw(DrawState *s)
 {
     SDL_Rect viewport;
@@ -173,7 +173,7 @@ Draw(DrawState *s)
     return SDL_TRUE;
 }
 
-void loop()
+static void loop(void)
 {
     int i;
     SDL_Event event;
diff --git a/test/testscale.c b/test/testscale.c
index 2f133f53b..d8139269b 100644
--- a/test/testscale.c
+++ b/test/testscale.c
@@ -21,9 +21,6 @@
 #include <SDL3/SDL_main.h>
 #include "testutils.h"
 
-#define WINDOW_WIDTH  640
-#define WINDOW_HEIGHT 480
-
 static SDLTest_CommonState *state;
 
 typedef struct
@@ -36,8 +33,8 @@ typedef struct
     int scale_direction;
 } DrawState;
 
-DrawState *drawstates;
-int done;
+static DrawState *drawstates;
+static int done;
 
 /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
 static void
@@ -47,7 +44,7 @@ quit(int rc)
     exit(rc);
 }
 
-void Draw(DrawState *s)
+static void Draw(DrawState *s)
 {
     SDL_Rect viewport;
 
@@ -77,7 +74,7 @@ void Draw(DrawState *s)
     SDL_RenderPresent(s->renderer);
 }
 
-void loop()
+static void loop(void)
 {
     int i;
     SDL_Event event;
diff --git a/test/testsem.c b/test/testsem.c
index 0a159aee3..db1940015 100644
--- a/test/testsem.c
+++ b/test/testsem.c
@@ -24,7 +24,7 @@
 #define NUM_OVERHEAD_OPS_MULT 10
 
 static SDL_sem *sem;
-int alive;
+static int alive;
 
 typedef struct Thread_State
 {
diff --git a/test/testshader.c b/test/testshader.c
index d61ddefe6..1cfdd74e9 100644
--- a/test/testshader.c
+++ b/test/testshader.c
@@ -231,7 +231,7 @@ static void DestroyShaderProgram(ShaderData *data)
     }
 }
 
-static SDL_bool InitShaders()
+static SDL_bool InitShaders(void)
 {
     int i;
 
@@ -285,7 +285,7 @@ static SDL_bool InitShaders()
     return SDL_TRUE;
 }
 
-static void QuitShaders()
+static void QuitShaders(void)
 {
     int i;
 
@@ -306,7 +306,7 @@ power_of_two(int input)
     return value;
 }
 
-GLuint
+static GLuint
 SDL_GL_LoadTexture(SDL_Surface *surface, GLfloat *texcoord)
 {
     GLuint texture;
@@ -356,7 +356,7 @@ SDL_GL_LoadTexture(SDL_Surface *surface, GLfloat *texcoord)
 }
 
 /* A general OpenGL initialization function.    Sets all of the initial parameters. */
-void InitGL(int Width, int Height) /* We call this right after our OpenGL window is created. */
+static void InitGL(int Width, int Height) /* We call this right after our OpenGL window is created. */
 {
     GLdouble aspect;
 
@@ -377,7 +377,7 @@ void InitGL(int Width, int Height) /* We call this right after our OpenGL window
 }
 
 /* The main drawing function. */
-void DrawGLScene(SDL_Window *window, GLuint texture, GLfloat *texcoord)
+static void DrawGLScene(SDL_Window *window, GLuint texture, GLfloat *texcoord)
 {
     /* Texture coordinate lookup, to make it simple */
     enum
diff --git a/test/testsprite.c b/test/testsprite.c
index a022a5464..75ac45d14 100644
--- a/test/testsprite.c
+++ b/test/testsprite.c
@@ -47,7 +47,7 @@ static int use_rendergeometry = 0;
 /* -1: infinite random moves (default); >=0: enables N deterministic moves */
 static int iterations = -1;
 
-int done;
+static int done;
 
 /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
 static void
@@ -65,7 +65,7 @@ quit(int rc)
     }
 }
 
-int LoadSprite(const char *file)
+static int LoadSprite(const char *file)
 {
     int i, w, h;
 
@@ -88,7 +88,7 @@ int LoadSprite(const char *file)
     return 0;
 }
 
-void MoveSprites(SDL_Renderer *renderer, SDL_Texture *sprite)
+static void MoveSprites(SDL_Renderer *renderer, SDL_Texture *sprite)
 {
     int i;
     SDL_Rect viewport;
@@ -396,7 +396,7 @@ void MoveSprites(SDL_Renderer *renderer, SDL_Texture *sprite)
     SDL_RenderPresent(renderer);
 }
 
-void loop()
+static void loop(void)
 {
     Uint64 now;
     int i;
diff --git a/test/testspriteminimal.c b/test/testspriteminimal.c
index f7267ce14..51eb59451 100644
--- a/test/testspriteminimal.c
+++ b/test/testspriteminimal.c
@@ -32,8 +32,8 @@ static SDL_FRect positions[NUM_SPRITES];
 static SDL_FRect velocities[NUM_SPRITES];
 static int sprite_w, sprite_h;
 
-SDL_Renderer *renderer;
-int done;
+static SDL_Renderer *renderer;
+static int done;
 
 /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
 static void
@@ -43,7 +43,7 @@ quit(int rc)
     exit(rc);
 }
 
-void MoveSprites()
+static void MoveSprites(void)
 {
     int i;
     int window_w = WINDOW_WIDTH;
@@ -77,7 +77,7 @@ void MoveSprites()
     SDL_RenderPresent(renderer);
 }
 
-void loop()
+static void loop(void)
 {
     SDL_Event event;
 
diff --git a/test/teststreaming.c b/test/teststreaming.c
index 72d0881d2..93045f374 100644
--- a/test/teststreaming.c
+++ b/test/teststreaming.c
@@ -32,7 +32,7 @@
 #define MOOSEFRAMES_COUNT 10
 
 /* *INDENT-OFF* */ /* clang-format off */
-SDL_Color MooseColors[84] = {
+static SDL_Color MooseColors[84] = {
     {49, 49, 49, 255}, {66, 24, 0, 255}, {66, 33, 0, 255}, {66, 66, 66, 255},
     {66, 115, 49, 255}, {74, 33, 0, 255}, {74, 41, 16, 255}, {82, 33, 8, 255},
     {82, 41, 8, 255}, {82, 49, 16, 255}, {82, 82, 82, 255}, {90, 41, 8, 255},
@@ -57,20 +57,20 @@ SDL_Color MooseColors[84] = {
 };
 /* *INDENT-ON* */ /* clang-format on */
 
-Uint8 MooseFrames[MOOSEFRAMES_COUNT][MOOSEFRAME_SIZE];
+static Uint8 MooseFrames[MOOSEFRAMES_COUNT][MOOSEFRAME_SIZE];
 
-SDL_Renderer *renderer;
-int frame;
-SDL_Texture *MooseTexture;
-SDL_bool done = SDL_FALSE;
+static SDL_Renderer *renderer;
+static int frame;
+static SDL_Texture *MooseTexture;
+static SDL_bool done = SDL_FALSE;
 
-void quit(int rc)
+static void quit(int rc)
 {
     SDL_Quit();
     exit(rc);
 }
 
-void UpdateTexture(SDL_Texture *texture)
+static void UpdateTexture(SDL_Texture *texture)
 {
     SDL_Color *color;
     Uint8 *src;
@@ -94,7 +94,7 @@ void UpdateTexture(SDL_Texture *texture)
     SDL_UnlockTexture(texture);
 }
 
-void loop()
+static void loop(void)
 {
     SDL_Event event;
 
diff --git a/test/testviewport.c b/test/testviewport.c
index a30859bc7..004f3f047 100644
--- a/test/testviewport.c
+++ b/test/testviewport.c
@@ -41,7 +41,7 @@ quit(int rc)
     exit(rc);
 }
 
-void DrawOnViewport(SDL_Renderer *renderer)
+static void DrawOnViewport(SDL_Renderer *renderer)
 {
     SDL_FRect rect;
     SDL_Rect cliprect;
@@ -102,7 +102,7 @@ void DrawOnViewport(SDL_Renderer *renderer)
     SDL_SetRenderClipRect(renderer, NULL);
 }
 
-void loop()
+static void loop(void)
 {
     SDL_Event event;
     int i;
diff --git a/test/testwm.c b/test/testwm.c
index 09668bf38..456446a67 100644
--- a/test/testwm.c
+++ b/test/testwm.c
@@ -21,7 +21,7 @@
 #include <SDL3/SDL_main.h>
 
 static SDLTest_CommonState *state;
-int done;
+static int done;
 
 static const char *cursorNames[] = {
     "arrow",
@@ -37,10 +37,10 @@ static const char *cursorNames[] = {
     "NO",
     "hand",
 };
-int system_cursor = -1;
-SDL_Cursor *cursor = NULL;
-SDL_bool relative_mode = SDL_FALSE;
-const SDL_DisplayMode *highlighted_mode = NULL;
+static int system_cursor = -1;
+static SDL_Cursor *cursor = NULL;
+static SDL_bool relative_mode = SDL_FALSE;
+static const SDL_DisplayMode *highlighted_mode = NULL;
 
 /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
 static void
@@ -150,7 +150,7 @@ draw_modes_menu(SDL_Window *window, SDL_Renderer *renderer, SDL_FRect viewport)
     }
 }
 
-void loop()
+static void loop(void)
 {
     int i;
     SDL_Event event;
diff --git a/test/torturethread.c b/test/torturethread.c
index 27d6167b0..7dd441180 100644
--- a/test/torturethread.c
+++ b/test/torturethread.c
@@ -30,7 +30,7 @@ quit(int rc)
     exit(rc);
 }
 
-int SDLCALL
+static int SDLCALL
 SubThreadFunc(void *data)
 {
     while (!*(int volatile *)data) {
@@ -39,7 +39,7 @@ SubThreadFunc(void *data)
     return 0;
 }
 
-int SDLCALL
+static int SDLCALL
 ThreadFunc(void *data)
 {
     SDL_Thread *sub_threads[NUMTHREADS];