diff --git a/examples/demo/02-woodeneye-008/woodeneye-008.c b/examples/demo/02-woodeneye-008/woodeneye-008.c
index 2c180cda01..97a72015e2 100644
--- a/examples/demo/02-woodeneye-008/woodeneye-008.c
+++ b/examples/demo/02-woodeneye-008/woodeneye-008.c
@@ -265,7 +265,7 @@ static void draw(SDL_Renderer *renderer, const float (*edges)[6], const Player p
             SDL_RenderLine(renderer, hor_origin-10, ver_origin, hor_origin+10, ver_origin);
         }
     }
-    SDL_SetRenderClipRect(renderer, 0);
+    SDL_SetRenderClipRect(renderer, NULL);
     SDL_SetRenderDrawColor(renderer, 255, 255, 255, 255);
     SDL_RenderDebugText(renderer, 0, 0, debug_string);
     SDL_RenderPresent(renderer);
diff --git a/src/core/linux/SDL_fcitx.c b/src/core/linux/SDL_fcitx.c
index 66b21d0471..ad10b55f04 100644
--- a/src/core/linux/SDL_fcitx.c
+++ b/src/core/linux/SDL_fcitx.c
@@ -60,7 +60,6 @@ static const char *GetAppName(void)
     if (exe_name) {
         return exe_name;
     }
-
     return "SDL_App";
 }
 
@@ -244,7 +243,7 @@ static bool FcitxCreateInputContext(SDL_DBusContext *dbus, const char *appname,
             DBusMessageIter args, array, sub;
             dbus->message_iter_init_append(msg, &args);
             dbus->message_iter_open_container(&args, DBUS_TYPE_ARRAY, "(ss)", &array);
-            dbus->message_iter_open_container(&array, DBUS_TYPE_STRUCT, 0, &sub);
+            dbus->message_iter_open_container(&array, DBUS_TYPE_STRUCT, NULL, &sub);
             dbus->message_iter_append_basic(&sub, DBUS_TYPE_STRING, &program);
             dbus->message_iter_append_basic(&sub, DBUS_TYPE_STRING, &appname);
             dbus->message_iter_close_container(&array, &sub);
diff --git a/src/core/unix/SDL_gtk.c b/src/core/unix/SDL_gtk.c
index 9b0c879b90..2d10aa180c 100644
--- a/src/core/unix/SDL_gtk.c
+++ b/src/core/unix/SDL_gtk.c
@@ -148,7 +148,7 @@ static bool InitGtk(void)
 
     gtk.g.signal_connect = signal_connect;
 
-    if (gtk.gtk.init_check(0, NULL) == GTK_FALSE) {
+    if (gtk.gtk.init_check(NULL, NULL) == GTK_FALSE) {
         QuitGtk();
         return SDL_SetError("Could not init GTK");
     }
diff --git a/src/test/SDL_test_harness.c b/src/test/SDL_test_harness.c
index d6a3b8d31a..8cc9938d7a 100644
--- a/src/test/SDL_test_harness.c
+++ b/src/test/SDL_test_harness.c
@@ -192,7 +192,6 @@ static SDL_TimerID SDLTest_SetTestTimeout(int timeout, SDL_TimerCallback callbac
         SDLTest_LogError("Timeout callback can't be NULL");
         return 0;
     }
-
     if (timeout < 0) {
         SDLTest_LogError("Timeout value must be bigger than zero.");
         return 0;
@@ -200,7 +199,7 @@ static SDL_TimerID SDLTest_SetTestTimeout(int timeout, SDL_TimerCallback callbac
 
     /* Set timer */
     timeoutInMilliseconds = timeout * 1000;
-    timerID = SDL_AddTimer(timeoutInMilliseconds, callback, 0x0);
+    timerID = SDL_AddTimer(timeoutInMilliseconds, callback, NULL);
     if (timerID == 0) {
         SDLTest_LogError("Creation of SDL timer failed: %s", SDL_GetError());
         return 0;
diff --git a/src/test/SDL_test_log.c b/src/test/SDL_test_log.c
index 95bc2a1123..d219ebb5a9 100644
--- a/src/test/SDL_test_log.c
+++ b/src/test/SDL_test_log.c
@@ -20,9 +20,7 @@
 */
 
 /*
-
  Used by the test framework and test cases.
-
 */
 
 /* quiet windows compiler warnings */
@@ -89,7 +87,7 @@ void SDLTest_Log(SDL_PRINTF_FORMAT_STRING const char *fmt, ...)
     va_end(list);
 
     /* Log with timestamp and newline */
-    SDL_LogMessage(SDL_LOG_CATEGORY_TEST, SDL_LOG_PRIORITY_INFO, " %s: %s", SDLTest_TimestampToString(time(0)), logMessage);
+    SDL_LogMessage(SDL_LOG_CATEGORY_TEST, SDL_LOG_PRIORITY_INFO, " %s: %s", SDLTest_TimestampToString(time(NULL)), logMessage);
 }
 
 /*
@@ -107,7 +105,7 @@ void SDLTest_LogError(SDL_PRINTF_FORMAT_STRING const char *fmt, ...)
     va_end(list);
 
     /* Log with timestamp and newline */
-    SDL_LogMessage(SDL_LOG_CATEGORY_TEST, SDL_LOG_PRIORITY_ERROR, "%s: %s", SDLTest_TimestampToString(time(0)), logMessage);
+    SDL_LogMessage(SDL_LOG_CATEGORY_TEST, SDL_LOG_PRIORITY_ERROR, "%s: %s", SDLTest_TimestampToString(time(NULL)), logMessage);
 }
 
 static char nibble_to_char(Uint8 nibble)
diff --git a/src/thread/pthread/SDL_systhread.c b/src/thread/pthread/SDL_systhread.c
index ae4a94c2e2..775690738f 100644
--- a/src/thread/pthread/SDL_systhread.c
+++ b/src/thread/pthread/SDL_systhread.c
@@ -166,7 +166,7 @@ void SDL_SYS_SetupThread(const char *name)
     for (i = 0; sig_list[i]; ++i) {
         sigaddset(&mask, sig_list[i]);
     }
-    pthread_sigmask(SIG_BLOCK, &mask, 0);
+    pthread_sigmask(SIG_BLOCK, &mask, NULL);
 #endif
 
 #ifdef PTHREAD_CANCEL_ASYNCHRONOUS
@@ -284,7 +284,7 @@ bool SDL_SYS_SetThreadPriority(SDL_ThreadPriority priority)
 
 void SDL_SYS_WaitThread(SDL_Thread *thread)
 {
-    pthread_join(thread->handle, 0);
+    pthread_join(thread->handle, NULL);
 }
 
 void SDL_SYS_DetachThread(SDL_Thread *thread)
diff --git a/src/video/SDL_blit_auto.c b/src/video/SDL_blit_auto.c
index 27cd9c714e..cf8b838e5d 100644
--- a/src/video/SDL_blit_auto.c
+++ b/src/video/SDL_blit_auto.c
@@ -39,7 +39,7 @@ static void SDL_Blit_XRGB8888_XRGB8888_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -128,7 +128,7 @@ static void SDL_Blit_XRGB8888_XRGB8888_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -227,7 +227,7 @@ static void SDL_Blit_XRGB8888_XRGB8888_Modulate_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -365,7 +365,7 @@ static void SDL_Blit_XRGB8888_XRGB8888_Modulate_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -460,7 +460,7 @@ static void SDL_Blit_XRGB8888_XBGR8888_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -552,7 +552,7 @@ static void SDL_Blit_XRGB8888_XBGR8888_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -651,7 +651,7 @@ static void SDL_Blit_XRGB8888_XBGR8888_Modulate_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -789,7 +789,7 @@ static void SDL_Blit_XRGB8888_XBGR8888_Modulate_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -884,7 +884,7 @@ static void SDL_Blit_XRGB8888_ARGB8888_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -977,7 +977,7 @@ static void SDL_Blit_XRGB8888_ARGB8888_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -1082,7 +1082,7 @@ static void SDL_Blit_XRGB8888_ARGB8888_Modulate_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -1225,7 +1225,7 @@ static void SDL_Blit_XRGB8888_ARGB8888_Modulate_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -1326,7 +1326,7 @@ static void SDL_Blit_XRGB8888_ABGR8888_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -1420,7 +1420,7 @@ static void SDL_Blit_XRGB8888_ABGR8888_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -1525,7 +1525,7 @@ static void SDL_Blit_XRGB8888_ABGR8888_Modulate_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -1668,7 +1668,7 @@ static void SDL_Blit_XRGB8888_ABGR8888_Modulate_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -1768,7 +1768,7 @@ static void SDL_Blit_XBGR8888_XRGB8888_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -1860,7 +1860,7 @@ static void SDL_Blit_XBGR8888_XRGB8888_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -1959,7 +1959,7 @@ static void SDL_Blit_XBGR8888_XRGB8888_Modulate_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -2097,7 +2097,7 @@ static void SDL_Blit_XBGR8888_XRGB8888_Modulate_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -2190,7 +2190,7 @@ static void SDL_Blit_XBGR8888_XBGR8888_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -2279,7 +2279,7 @@ static void SDL_Blit_XBGR8888_XBGR8888_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -2378,7 +2378,7 @@ static void SDL_Blit_XBGR8888_XBGR8888_Modulate_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -2516,7 +2516,7 @@ static void SDL_Blit_XBGR8888_XBGR8888_Modulate_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -2612,7 +2612,7 @@ static void SDL_Blit_XBGR8888_ARGB8888_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -2706,7 +2706,7 @@ static void SDL_Blit_XBGR8888_ARGB8888_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -2811,7 +2811,7 @@ static void SDL_Blit_XBGR8888_ARGB8888_Modulate_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -2954,7 +2954,7 @@ static void SDL_Blit_XBGR8888_ARGB8888_Modulate_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -3054,7 +3054,7 @@ static void SDL_Blit_XBGR8888_ABGR8888_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -3147,7 +3147,7 @@ static void SDL_Blit_XBGR8888_ABGR8888_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -3252,7 +3252,7 @@ static void SDL_Blit_XBGR8888_ABGR8888_Modulate_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -3395,7 +3395,7 @@ static void SDL_Blit_XBGR8888_ABGR8888_Modulate_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -3494,7 +3494,7 @@ static void SDL_Blit_ARGB8888_XRGB8888_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -3611,7 +3611,7 @@ static void SDL_Blit_ARGB8888_XRGB8888_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -3736,7 +3736,7 @@ static void SDL_Blit_ARGB8888_XRGB8888_Modulate_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -3875,7 +3875,7 @@ static void SDL_Blit_ARGB8888_XRGB8888_Modulate_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -3973,7 +3973,7 @@ static void SDL_Blit_ARGB8888_XBGR8888_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -4091,7 +4091,7 @@ static void SDL_Blit_ARGB8888_XBGR8888_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -4216,7 +4216,7 @@ static void SDL_Blit_ARGB8888_XBGR8888_Modulate_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -4355,7 +4355,7 @@ static void SDL_Blit_ARGB8888_XBGR8888_Modulate_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -4451,7 +4451,7 @@ static void SDL_Blit_ARGB8888_ARGB8888_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -4571,7 +4571,7 @@ static void SDL_Blit_ARGB8888_ARGB8888_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -4706,7 +4706,7 @@ static void SDL_Blit_ARGB8888_ARGB8888_Modulate_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -4853,7 +4853,7 @@ static void SDL_Blit_ARGB8888_ARGB8888_Modulate_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -4956,7 +4956,7 @@ static void SDL_Blit_ARGB8888_ABGR8888_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -5079,7 +5079,7 @@ static void SDL_Blit_ARGB8888_ABGR8888_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -5214,7 +5214,7 @@ static void SDL_Blit_ARGB8888_ABGR8888_Modulate_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -5361,7 +5361,7 @@ static void SDL_Blit_ARGB8888_ABGR8888_Modulate_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -5463,7 +5463,7 @@ static void SDL_Blit_RGBA8888_XRGB8888_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -5580,7 +5580,7 @@ static void SDL_Blit_RGBA8888_XRGB8888_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -5705,7 +5705,7 @@ static void SDL_Blit_RGBA8888_XRGB8888_Modulate_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -5844,7 +5844,7 @@ static void SDL_Blit_RGBA8888_XRGB8888_Modulate_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -5942,7 +5942,7 @@ static void SDL_Blit_RGBA8888_XBGR8888_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -6060,7 +6060,7 @@ static void SDL_Blit_RGBA8888_XBGR8888_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -6185,7 +6185,7 @@ static void SDL_Blit_RGBA8888_XBGR8888_Modulate_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -6324,7 +6324,7 @@ static void SDL_Blit_RGBA8888_XBGR8888_Modulate_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -6421,7 +6421,7 @@ static void SDL_Blit_RGBA8888_ARGB8888_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -6543,7 +6543,7 @@ static void SDL_Blit_RGBA8888_ARGB8888_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -6678,7 +6678,7 @@ static void SDL_Blit_RGBA8888_ARGB8888_Modulate_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -6825,7 +6825,7 @@ static void SDL_Blit_RGBA8888_ARGB8888_Modulate_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -6928,7 +6928,7 @@ static void SDL_Blit_RGBA8888_ABGR8888_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -7051,7 +7051,7 @@ static void SDL_Blit_RGBA8888_ABGR8888_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -7186,7 +7186,7 @@ static void SDL_Blit_RGBA8888_ABGR8888_Modulate_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -7333,7 +7333,7 @@ static void SDL_Blit_RGBA8888_ABGR8888_Modulate_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -7436,7 +7436,7 @@ static void SDL_Blit_ABGR8888_XRGB8888_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -7554,7 +7554,7 @@ static void SDL_Blit_ABGR8888_XRGB8888_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -7679,7 +7679,7 @@ static void SDL_Blit_ABGR8888_XRGB8888_Modulate_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -7818,7 +7818,7 @@ static void SDL_Blit_ABGR8888_XRGB8888_Modulate_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -7915,7 +7915,7 @@ static void SDL_Blit_ABGR8888_XBGR8888_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -8032,7 +8032,7 @@ static void SDL_Blit_ABGR8888_XBGR8888_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -8157,7 +8157,7 @@ static void SDL_Blit_ABGR8888_XBGR8888_Modulate_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -8296,7 +8296,7 @@ static void SDL_Blit_ABGR8888_XBGR8888_Modulate_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -8394,7 +8394,7 @@ static void SDL_Blit_ABGR8888_ARGB8888_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -8517,7 +8517,7 @@ static void SDL_Blit_ABGR8888_ARGB8888_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -8652,7 +8652,7 @@ static void SDL_Blit_ABGR8888_ARGB8888_Modulate_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -8799,7 +8799,7 @@ static void SDL_Blit_ABGR8888_ARGB8888_Modulate_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -8900,7 +8900,7 @@ static void SDL_Blit_ABGR8888_ABGR8888_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -9020,7 +9020,7 @@ static void SDL_Blit_ABGR8888_ABGR8888_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -9155,7 +9155,7 @@ static void SDL_Blit_ABGR8888_ABGR8888_Modulate_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -9302,7 +9302,7 @@ static void SDL_Blit_ABGR8888_ABGR8888_Modulate_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -9405,7 +9405,7 @@ static void SDL_Blit_BGRA8888_XRGB8888_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -9523,7 +9523,7 @@ static void SDL_Blit_BGRA8888_XRGB8888_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -9648,7 +9648,7 @@ static void SDL_Blit_BGRA8888_XRGB8888_Modulate_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -9787,7 +9787,7 @@ static void SDL_Blit_BGRA8888_XRGB8888_Modulate_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -9884,7 +9884,7 @@ static void SDL_Blit_BGRA8888_XBGR8888_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -10001,7 +10001,7 @@ static void SDL_Blit_BGRA8888_XBGR8888_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -10126,7 +10126,7 @@ static void SDL_Blit_BGRA8888_XBGR8888_Modulate_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -10265,7 +10265,7 @@ static void SDL_Blit_BGRA8888_XBGR8888_Modulate_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -10363,7 +10363,7 @@ static void SDL_Blit_BGRA8888_ARGB8888_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -10486,7 +10486,7 @@ static void SDL_Blit_BGRA8888_ARGB8888_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -10621,7 +10621,7 @@ static void SDL_Blit_BGRA8888_ARGB8888_Modulate_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -10768,7 +10768,7 @@ static void SDL_Blit_BGRA8888_ARGB8888_Modulate_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -10870,7 +10870,7 @@ static void SDL_Blit_BGRA8888_ABGR8888_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -10992,7 +10992,7 @@ static void SDL_Blit_BGRA8888_ABGR8888_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -11127,7 +11127,7 @@ static void SDL_Blit_BGRA8888_ABGR8888_Modulate_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
@@ -11274,7 +11274,7 @@ static void SDL_Blit_BGRA8888_ABGR8888_Modulate_Blend_Scale(SDL_BlitInfo *info)
     posy = incy / 2;
 
     while (info->dst_h--) {
-        Uint32 *src = 0;
+        Uint32 *src = NULL;
         Uint32 *dst = (Uint32 *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
diff --git a/src/video/SDL_blit_slow.c b/src/video/SDL_blit_slow.c
index 63f08f2ddc..1db9cce217 100644
--- a/src/video/SDL_blit_slow.c
+++ b/src/video/SDL_blit_slow.c
@@ -90,7 +90,7 @@ void SDL_Blit_Slow(SDL_BlitInfo *info)
     posy = incy / 2; // start at the middle of pixel
 
     while (info->dst_h--) {
-        Uint8 *src = 0;
+        Uint8 *src = NULL;
         Uint8 *dst = info->dst;
         int n = info->dst_w;
         posx = incx / 2; // start at the middle of pixel
@@ -897,7 +897,7 @@ void SDL_Blit_Slow_Float(SDL_BlitInfo *info)
     posy = incy / 2; // start at the middle of pixel
 
     while (info->dst_h--) {
-        Uint8 *src = 0;
+        Uint8 *src = NULL;
         Uint8 *dst = info->dst;
         int n = info->dst_w;
         posx = incx / 2; // start at the middle of pixel
diff --git a/src/video/SDL_video.c b/src/video/SDL_video.c
index 17dc158c08..e259c7008a 100644
--- a/src/video/SDL_video.c
+++ b/src/video/SDL_video.c
@@ -1727,7 +1727,7 @@ SDL_VideoDisplay *SDL_GetVideoDisplayForFullscreenWindow(SDL_Window *window)
 {
     SDL_DisplayID displayID = 0;
 
-    CHECK_WINDOW_MAGIC(window, 0);
+    CHECK_WINDOW_MAGIC(window, NULL);
 
     // An explicit fullscreen display overrides all
     if (window->current_fullscreen_mode.displayID) {
diff --git a/src/video/sdlgenblit.pl b/src/video/sdlgenblit.pl
index 5090396e7a..9a61a3c28b 100755
--- a/src/video/sdlgenblit.pl
+++ b/src/video/sdlgenblit.pl
@@ -593,7 +593,7 @@ __EOF__
     posy = incy / 2;
 
     while (info->dst_h--) {
-        $format_type{$src} *src = 0;
+        $format_type{$src} *src = NULL;
         $format_type{$dst} *dst = ($format_type{$dst} *)info->dst;
         int n = info->dst_w;
         posx = incx / 2;
diff --git a/src/video/stb_image.h b/src/video/stb_image.h
index 1ce63899ec..ad1bb25212 100644
--- a/src/video/stb_image.h
+++ b/src/video/stb_image.h
@@ -3408,8 +3408,8 @@ static int stbi__free_jpeg_components(stbi__jpeg *z, int ncomp, int why)
       }
       if (z->img_comp[i].raw_coeff) {
          STBI_FREE(z->img_comp[i].raw_coeff);
-         z->img_comp[i].raw_coeff = 0;
-         z->img_comp[i].coeff = 0;
+         z->img_comp[i].raw_coeff = NULL;
+         z->img_comp[i].coeff = NULL;
       }
       if (z->img_comp[i].linebuf) {
          STBI_FREE(z->img_comp[i].linebuf);
@@ -3489,8 +3489,8 @@ static int stbi__process_frame_header(stbi__jpeg *z, int scan)
       // so these muls can't overflow with 32-bit ints (which we require)
       z->img_comp[i].w2 = z->img_mcu_x * z->img_comp[i].h * 8;
       z->img_comp[i].h2 = z->img_mcu_y * z->img_comp[i].v * 8;
-      z->img_comp[i].coeff = 0;
-      z->img_comp[i].raw_coeff = 0;
+      z->img_comp[i].coeff = NULL;
+      z->img_comp[i].raw_coeff = NULL;
       z->img_comp[i].linebuf = NULL;
       z->img_comp[i].raw_data = stbi__malloc_mad2(z->img_comp[i].w2, z->img_comp[i].h2, 15);
       if (z->img_comp[i].raw_data == NULL)
diff --git a/src/video/x11/SDL_x11clipboard.c b/src/video/x11/SDL_x11clipboard.c
index 7f083c3f5f..4da92d1c66 100644
--- a/src/video/x11/SDL_x11clipboard.c
+++ b/src/video/x11/SDL_x11clipboard.c
@@ -52,7 +52,7 @@ Window GetWindow(SDL_VideoDevice *_this)
         XSetWindowAttributes xattr;
         data->clipboard_window = X11_XCreateWindow(dpy, parent, -10, -10, 1, 1, 0,
                                                    CopyFromParent, InputOnly,
-                                                   CopyFromParent, 0, &xattr);
+                                                   NULL, 0, &xattr);
 
         X11_XSelectInput(dpy, data->clipboard_window, PropertyChangeMask);
         X11_XFlush(data->display);
@@ -248,7 +248,7 @@ static void *GetSelectionData(SDL_VideoDevice *_this, Atom selection_type,
 
                 if (incr_success == false) {
                     SDL_free(data);
-                    data = 0;
+                    data = NULL;
                     *length = 0;
                 }
             }
diff --git a/src/video/x11/SDL_x11framebuffer.c b/src/video/x11/SDL_x11framebuffer.c
index c1a429560e..018de3b67a 100644
--- a/src/video/x11/SDL_x11framebuffer.c
+++ b/src/video/x11/SDL_x11framebuffer.c
@@ -89,7 +89,7 @@ bool X11_CreateWindowFramebuffer(SDL_VideoDevice *_this, SDL_Window *window, SDL
 
         shminfo->shmid = shmget(IPC_PRIVATE, (size_t)h * (*pitch), IPC_CREAT | 0777);
         if (shminfo->shmid >= 0) {
-            shminfo->shmaddr = (char *)shmat(shminfo->shmid, 0, 0);
+            shminfo->shmaddr = (char *)shmat(shminfo->shmid, NULL, 0);
             shminfo->readOnly = False;
             if (shminfo->shmaddr != (char *)-1) {
                 shm_error = False;
diff --git a/src/video/x11/SDL_x11opengl.c b/src/video/x11/SDL_x11opengl.c
index 041b5e8895..aa454cec53 100644
--- a/src/video/x11/SDL_x11opengl.c
+++ b/src/video/x11/SDL_x11opengl.c
@@ -342,9 +342,9 @@ static void X11_GL_InitExtensions(SDL_VideoDevice *_this)
     const int screen = DefaultScreen(display);
     XVisualInfo *vinfo = NULL;
     Window w = 0;
-    GLXContext prev_ctx = 0;
+    GLXContext prev_ctx = NULL;
     GLXDrawable prev_drawable = 0;
-    GLXContext context = 0;
+    GLXContext context = NULL;
     const char *(*glXQueryExtensionsStringFunc)(Display *, int);
     const char *extensions;
 
diff --git a/src/video/x11/SDL_x11pen.c b/src/video/x11/SDL_x11pen.c
index 9374b23c84..24bec559b0 100644
--- a/src/video/x11/SDL_x11pen.c
+++ b/src/video/x11/SDL_x11pen.c
@@ -202,9 +202,9 @@ static X11_PenHandle *X11_MaybeAddPen(SDL_VideoDevice *_this, const XIDeviceInfo
 
     if ((dev->use != XISlavePointer && (dev->use != XIFloatingSlave)) || dev->enabled == 0 || !X11_XInput2DeviceIsPen(_this, dev)) {
         return NULL;  // Only track physical devices that are enabled and look like pens
-    } else if ((handle = X11_FindPenByDeviceID(dev->deviceid)) != 0) {
+    } else if ((handle = X11_FindPenByDeviceID(dev->deviceid)) != NULL) {
         return handle;  // already have this pen, skip it.
-    } else if ((handle = SDL_calloc(1, sizeof (*handle))) == NULL) {
+    } else if ((handle = SDL_calloc(1, sizeof(*handle))) == NULL) {
         return NULL;  // oh well.
     }
 
diff --git a/src/video/x11/SDL_x11toolkit.c b/src/video/x11/SDL_x11toolkit.c
index d71b6bc74c..6f895fbd78 100644
--- a/src/video/x11/SDL_x11toolkit.c
+++ b/src/video/x11/SDL_x11toolkit.c
@@ -216,7 +216,7 @@ static void X11Toolkit_InitWindowPixmap(SDL_ToolkitWindowX11 *data) {
                 }
 
                 data->shm_info.readOnly = False;
-                data->shm_info.shmaddr = data->image->data = (char *)shmat(data->shm_info.shmid, 0, 0);
+                data->shm_info.shmaddr = data->image->data = (char *)shmat(data->shm_info.shmid, NULL, 0);
                 if (((signed char *)data->shm_info.shmaddr) == (signed char *)-1) {
                     XDestroyImage(data->image);
                     data->shm = false;
@@ -232,7 +232,7 @@ static void X11Toolkit_InitWindowPixmap(SDL_ToolkitWindowX11 *data) {
                 if (g_shm_error) {
                     XDestroyImage(data->image);
                     shmdt(data->shm_info.shmaddr);
-                    shmctl(data->shm_info.shmid, IPC_RMID, 0);
+                    shmctl(data->shm_info.shmid, IPC_RMID, NULL);
                     data->image = NULL;
                     data->shm = false;
                     return;
@@ -248,7 +248,7 @@ static void X11Toolkit_InitWindowPixmap(SDL_ToolkitWindowX11 *data) {
                     }
                 }
 
-                shmctl(data->shm_info.shmid, IPC_RMID, 0);
+                shmctl(data->shm_info.shmid, IPC_RMID, NULL);
             } else {
                 data->shm = false;
             }
diff --git a/test/testgles2.c b/test/testgles2.c
index 2f054fcaf6..312b523ba6 100644
--- a/test/testgles2.c
+++ b/test/testgles2.c
@@ -880,13 +880,13 @@ int main(int argc, char *argv[])
         GL_CHECK(ctx.glGenBuffers(1, &data->position_buffer));
         GL_CHECK(ctx.glBindBuffer(GL_ARRAY_BUFFER, data->position_buffer));
         GL_CHECK(ctx.glBufferData(GL_ARRAY_BUFFER, sizeof(g_vertices), g_vertices, GL_STATIC_DRAW));
-        GL_CHECK(ctx.glVertexAttribPointer(data->attr_position, 3, GL_FLOAT, GL_FALSE, 0, 0));
+        GL_CHECK(ctx.glVertexAttribPointer(data->attr_position, 3, GL_FLOAT, GL_FALSE, 0, NULL));
         GL_CHECK(ctx.glBindBuffer(GL_ARRAY_BUFFER, 0));
 
         GL_CHECK(ctx.glGenBuffers(1, &data->color_buffer));
         GL_CHECK(ctx.glBindBuffer(GL_ARRAY_BUFFER, data->color_buffer));
         GL_CHECK(ctx.glBufferData(GL_ARRAY_BUFFER, sizeof(g_colors), g_colors, GL_STATIC_DRAW));
-        GL_CHECK(ctx.glVertexAttribPointer(data->attr_color, 3, GL_FLOAT, GL_FALSE, 0, 0));
+        GL_CHECK(ctx.glVertexAttribPointer(data->attr_color, 3, GL_FLOAT, GL_FALSE, 0, NULL));
         GL_CHECK(ctx.glBindBuffer(GL_ARRAY_BUFFER, 0));
 
         GL_CHECK(ctx.glEnable(GL_CULL_FACE));