diff --git a/build-scripts/stdlib_checks.py b/build-scripts/check_stdlib_usage.py
similarity index 98%
rename from build-scripts/stdlib_checks.py
rename to build-scripts/check_stdlib_usage.py
index d710c9096..830a04a3c 100755
--- a/build-scripts/stdlib_checks.py
+++ b/build-scripts/check_stdlib_usage.py
@@ -81,6 +81,7 @@ words = [
     'lroundf',
     'ltoa',
     'malloc',
+    'memalign',
     'memcmp',
     'memcpy',
     'memcpy4',
@@ -199,7 +200,7 @@ def find_symbols_in_file(file, regex):
                 if regex.match(l):
 
                     # free() allowed here
-                    if "This should NOT be SDL_free" in l:
+                    if "This should NOT be SDL_" in l:
                         continue
 
                     # double check
diff --git a/src/SDL_assert.c b/src/SDL_assert.c
index 50ac16572..acde7f4a0 100644
--- a/src/SDL_assert.c
+++ b/src/SDL_assert.c
@@ -270,7 +270,7 @@ static SDL_AssertState SDLCALL SDL_PromptAssertion(const SDL_AssertData *data, v
             } else {
                 okay = SDL_FALSE;
             }
-            free(buf);
+            free(buf);  /* This should NOT be SDL_free() */
 
             if (okay) {
                 break;
diff --git a/src/audio/alsa/SDL_alsa_audio.c b/src/audio/alsa/SDL_alsa_audio.c
index 27e5557ea..a73204768 100644
--- a/src/audio/alsa/SDL_alsa_audio.c
+++ b/src/audio/alsa/SDL_alsa_audio.c
@@ -622,7 +622,7 @@ static int ALSA_OpenDevice(SDL_AudioDevice *_this, const char *devname)
                 _this->hidden->swizzle_func = no_swizzle;
             }
         }
-        free(chmap);
+        free(chmap); /* This should NOT be SDL_free() */
     }
 #endif /* SND_CHMAP_API_VERSION */
 
@@ -743,7 +743,7 @@ static void add_device(const int iscapture, const char *name, void *hint, ALSA_D
     handle = SDL_strdup(name);
     if (handle == NULL) {
         if (hint) {
-            free(desc);
+            free(desc); /* This should NOT be SDL_free() */
         }
         SDL_free(dev);
         return;
@@ -755,7 +755,7 @@ static void add_device(const int iscapture, const char *name, void *hint, ALSA_D
      */
     SDL_AddAudioDevice(iscapture, desc, NULL, handle);
     if (hint) {
-        free(desc);
+        free(desc); /* This should NOT be SDL_free() */
     }
     dev->name = handle;
     dev->iscapture = iscapture;
@@ -814,7 +814,7 @@ static void ALSA_HotplugIteration(void)
                 }
             }
 
-            free(name);
+            free(name); /* This should NOT be SDL_free() */
         }
 
         /* look through the list of device names to find matches */
@@ -839,10 +839,10 @@ static void ALSA_HotplugIteration(void)
                 SDL_bool have_output = SDL_FALSE;
                 SDL_bool have_input = SDL_FALSE;
 
-                free(ioid);
+                free(ioid); /* This should NOT be SDL_free() */
 
                 if (!isoutput && !isinput) {
-                    free(name);
+                    free(name); /* This should NOT be SDL_free() */
                     continue;
                 }
 
@@ -876,7 +876,7 @@ static void ALSA_HotplugIteration(void)
                 }
             }
 
-            free(name);
+            free(name); /* This should NOT be SDL_free() */
         }
 
         ALSA_snd_device_name_free_hint(hints);
diff --git a/src/audio/n3ds/SDL_n3dsaudio.c b/src/audio/n3ds/SDL_n3dsaudio.c
index 254bca019..1d0bff66e 100644
--- a/src/audio/n3ds/SDL_n3dsaudio.c
+++ b/src/audio/n3ds/SDL_n3dsaudio.c
@@ -238,7 +238,7 @@ static void N3DSAUDIO_CloseDevice(SDL_AudioDevice *_this)
 
     if (!_this->hidden->isCancelled) {
         ndspChnReset(0);
-        memset(_this->hidden->waveBuf, 0, sizeof(ndspWaveBuf) * NUM_BUFFERS);
+        SDL_memset(_this->hidden->waveBuf, 0, sizeof(ndspWaveBuf) * NUM_BUFFERS);
         CondVar_Broadcast(&_this->hidden->cv);
     }
 
diff --git a/src/audio/ps2/SDL_ps2audio.c b/src/audio/ps2/SDL_ps2audio.c
index 362f1e079..f14eb6ee7 100644
--- a/src/audio/ps2/SDL_ps2audio.c
+++ b/src/audio/ps2/SDL_ps2audio.c
@@ -26,7 +26,6 @@
 #include "SDL_ps2audio.h"
 
 #include <kernel.h>
-#include <malloc.h>
 #include <audsrv.h>
 #include <ps2_audio_driver.h>
 
@@ -75,7 +74,7 @@ static int PS2AUDIO_OpenDevice(SDL_AudioDevice *_this, const char *devname)
     audsrv_set_volume(MAX_VOLUME);
 
     if (_this->hidden->channel < 0) {
-        free(_this->hidden->rawbuf);
+        SDL_aligned_free(_this->hidden->rawbuf);
         _this->hidden->rawbuf = NULL;
         return SDL_SetError("Couldn't reserve hardware channel");
     }
@@ -87,7 +86,7 @@ static int PS2AUDIO_OpenDevice(SDL_AudioDevice *_this, const char *devname)
        be a multiple of 64 bytes.  Our sample count is already a multiple of
        64, so spec->size should be a multiple of 64 as well. */
     mixlen = _this->spec.size * NUM_BUFFERS;
-    _this->hidden->rawbuf = (Uint8 *)memalign(64, mixlen);
+    _this->hidden->rawbuf = (Uint8 *)SDL_aligned_alloc(64, mixlen);
     if (_this->hidden->rawbuf == NULL) {
         return SDL_SetError("Couldn't allocate mixing buffer");
     }
@@ -128,7 +127,7 @@ static void PS2AUDIO_CloseDevice(SDL_AudioDevice *_this)
     }
 
     if (_this->hidden->rawbuf != NULL) {
-        free(_this->hidden->rawbuf);
+        SDL_aligned_free(_this->hidden->rawbuf);
         _this->hidden->rawbuf = NULL;
     }
 }
diff --git a/src/audio/psp/SDL_pspaudio.c b/src/audio/psp/SDL_pspaudio.c
index 5d35c373e..eda9c74ee 100644
--- a/src/audio/psp/SDL_pspaudio.c
+++ b/src/audio/psp/SDL_pspaudio.c
@@ -25,7 +25,6 @@
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
-#include <malloc.h> /* memalign() */
 
 #include "../SDL_audio_c.h"
 #include "../SDL_audiodev_c.h"
@@ -92,7 +91,7 @@ static int PSPAUDIO_OpenDevice(SDL_AudioDevice *_this, const char *devname)
     }
 
     if (_this->hidden->channel < 0) {
-        free(_this->hidden->rawbuf);
+        SDL_aligned_free(_this->hidden->rawbuf);
         _this->hidden->rawbuf = NULL;
         return SDL_SetError("Couldn't reserve hardware channel");
     }
@@ -104,7 +103,7 @@ static int PSPAUDIO_OpenDevice(SDL_AudioDevice *_this, const char *devname)
        be a multiple of 64 bytes.  Our sample count is already a multiple of
        64, so spec->size should be a multiple of 64 as well. */
     mixlen = _this->spec.size * NUM_BUFFERS;
-    _this->hidden->rawbuf = (Uint8 *)memalign(64, mixlen);
+    _this->hidden->rawbuf = (Uint8 *)SDL_aligned_alloc(64, mixlen);
     if (_this->hidden->rawbuf == NULL) {
         return SDL_SetError("Couldn't allocate mixing buffer");
     }
@@ -154,7 +153,7 @@ static void PSPAUDIO_CloseDevice(SDL_AudioDevice *_this)
     }
 
     if (_this->hidden->rawbuf != NULL) {
-        free(_this->hidden->rawbuf);
+        SDL_aligned_free(_this->hidden->rawbuf);
         _this->hidden->rawbuf = NULL;
     }
 }
diff --git a/src/audio/vita/SDL_vitaaudio.c b/src/audio/vita/SDL_vitaaudio.c
index 0c76c5343..5cd40e699 100644
--- a/src/audio/vita/SDL_vitaaudio.c
+++ b/src/audio/vita/SDL_vitaaudio.c
@@ -25,7 +25,6 @@
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
-#include <malloc.h> /* memalign() */
 
 #include "../SDL_audio_c.h"
 #include "../SDL_audiodev_c.h"
@@ -96,7 +95,7 @@ static int VITAAUD_OpenDevice(SDL_AudioDevice *_this, const char *devname)
        be a multiple of 64 bytes.  Our sample count is already a multiple of
        64, so spec->size should be a multiple of 64 as well. */
     mixlen = _this->spec.size * NUM_BUFFERS;
-    _this->hidden->rawbuf = (Uint8 *)memalign(64, mixlen);
+    _this->hidden->rawbuf = (Uint8 *)SDL_aligned_alloc(64, mixlen);
     if (_this->hidden->rawbuf == NULL) {
         return SDL_SetError("Couldn't allocate mixing buffer");
     }
@@ -114,7 +113,7 @@ static int VITAAUD_OpenDevice(SDL_AudioDevice *_this, const char *devname)
 
     _this->hidden->port = sceAudioOutOpenPort(port, _this->spec.samples, _this->spec.freq, format);
     if (_this->hidden->port < 0) {
-        free(_this->hidden->rawbuf);
+        SDL_aligned_free(_this->hidden->rawbuf);
         _this->hidden->rawbuf = NULL;
         return SDL_SetError("Couldn't open audio out port: %x", _this->hidden->port);
     }
@@ -162,7 +161,7 @@ static void VITAAUD_CloseDevice(SDL_AudioDevice *_this)
     }
 
     if (!_this->iscapture && _this->hidden->rawbuf != NULL) {
-        free(_this->hidden->rawbuf); /* this uses memalign(), not SDL_malloc(). */
+        SDL_aligned_free(_this->hidden->rawbuf);
         _this->hidden->rawbuf = NULL;
     }
 }
diff --git a/src/core/openbsd/SDL_wscons_kbd.c b/src/core/openbsd/SDL_wscons_kbd.c
index afb6e7cba..f54f1d395 100644
--- a/src/core/openbsd/SDL_wscons_kbd.c
+++ b/src/core/openbsd/SDL_wscons_kbd.c
@@ -42,7 +42,7 @@
 
 #define RETIFIOCTLERR(x) \
     if ((x) == -1) {     \
-        free(input);     \
+        SDL_free(input); \
         input = NULL;    \
         return NULL;     \
     }
@@ -424,13 +424,13 @@ static SDL_WSCONS_input_data *SDL_WSCONS_Init_Keyboard(const char *dev)
     }
     input->fd = open(dev, O_RDWR | O_NONBLOCK | O_CLOEXEC);
     if (input->fd == -1) {
-        free(input);
+        SDL_free(input);
         input = NULL;
         return NULL;
     }
     input->keymap.map = SDL_calloc(sizeof(struct wscons_keymap), KS_NUMKEYCODES);
     if (input->keymap.map == NULL) {
-        free(input);
+        SDL_free(input);
         return NULL;
     }
     input->keymap.maplen = KS_NUMKEYCODES;
@@ -471,7 +471,7 @@ void SDL_WSCONS_Quit()
                 close(input->fd);
                 input->fd = -1;
             }
-            free(input);
+            SDL_free(input);
             input = NULL;
         }
         inputs[i] = NULL;
diff --git a/src/core/openbsd/SDL_wscons_mouse.c b/src/core/openbsd/SDL_wscons_mouse.c
index c45dc6463..c3378153c 100644
--- a/src/core/openbsd/SDL_wscons_mouse.c
+++ b/src/core/openbsd/SDL_wscons_mouse.c
@@ -46,7 +46,7 @@ SDL_WSCONS_mouse_input_data *SDL_WSCONS_Init_Mouse()
     }
     mouseInputData->fd = open("/dev/wsmouse", O_RDWR | O_NONBLOCK | O_CLOEXEC);
     if (mouseInputData->fd == -1) {
-        free(mouseInputData);
+        SDL_free(mouseInputData);
         return NULL;
     }
 #ifdef WSMOUSEIO_SETMODE
@@ -129,5 +129,5 @@ void SDL_WSCONS_Quit_Mouse(SDL_WSCONS_mouse_input_data *inputData)
         return;
     }
     close(inputData->fd);
-    free(inputData);
+    SDL_free(inputData);
 }
diff --git a/src/cpuinfo/SDL_cpuinfo.c b/src/cpuinfo/SDL_cpuinfo.c
index cb39b0117..7eeb14e0c 100644
--- a/src/cpuinfo/SDL_cpuinfo.c
+++ b/src/cpuinfo/SDL_cpuinfo.c
@@ -1066,7 +1066,7 @@ int SDL_GetSystemRAM(void)
             if (get_system_info(&info) == B_OK) {
                 /* To have an accurate amount, we also take in account the inaccessible pages (aka ignored)
                   which is a bit handier compared to the legacy system's api (i.e. used_pages).*/
-                SDL_SystemRAM = (int)round((info.max_pages + info.ignored_pages > 0 ? info.ignored_pages : 0) * B_PAGE_SIZE / 1048576.0);
+                SDL_SystemRAM = (int)SDL_round((info.max_pages + info.ignored_pages > 0 ? info.ignored_pages : 0) * B_PAGE_SIZE / 1048576.0);
             }
         }
 #endif
diff --git a/src/filesystem/ps2/SDL_sysfilesystem.c b/src/filesystem/ps2/SDL_sysfilesystem.c
index 92e87a4d0..0636fce28 100644
--- a/src/filesystem/ps2/SDL_sysfilesystem.c
+++ b/src/filesystem/ps2/SDL_sysfilesystem.c
@@ -70,7 +70,7 @@ static void recursive_mkdir(const char *dir)
         }
     }
 
-    free(base);
+    SDL_free(base);
     mkdir(tmp, S_IRWXU);
 }
 
@@ -95,7 +95,7 @@ char *SDL_GetPrefPath(const char *org, const char *app)
     } else {
         SDL_snprintf(retval, len, "%s%s/", base, app);
     }
-    free(base);
+    SDL_free(base);
 
     recursive_mkdir(retval);
 
diff --git a/src/filesystem/psp/SDL_sysfilesystem.c b/src/filesystem/psp/SDL_sysfilesystem.c
index 60c510e5e..3fdd71927 100644
--- a/src/filesystem/psp/SDL_sysfilesystem.c
+++ b/src/filesystem/psp/SDL_sysfilesystem.c
@@ -63,7 +63,7 @@ char *SDL_GetPrefPath(const char *org, const char *app)
     } else {
         SDL_snprintf(retval, len, "%s%s/", base, app);
     }
-    free(base);
+    SDL_free(base);
 
     mkdir(retval, 0755);
     return retval;
diff --git a/src/render/ps2/SDL_render_ps2.c b/src/render/ps2/SDL_render_ps2.c
index 9a9708cd4..a1828286a 100644
--- a/src/render/ps2/SDL_render_ps2.c
+++ b/src/render/ps2/SDL_render_ps2.c
@@ -111,7 +111,7 @@ static int PS2_CreateTexture(SDL_Renderer *renderer, SDL_Texture *texture)
     ps2_tex->Width = texture->w;
     ps2_tex->Height = texture->h;
     ps2_tex->PSM = PixelFormatToPS2PSM(texture->format);
-    ps2_tex->Mem = memalign(128, gsKit_texture_size_ee(ps2_tex->Width, ps2_tex->Height, ps2_tex->PSM));
+    ps2_tex->Mem = SDL_aligned_alloc(128, gsKit_texture_size_ee(ps2_tex->Width, ps2_tex->Height, ps2_tex->PSM));
 
     if (!ps2_tex->Mem) {
         SDL_free(ps2_tex);
@@ -541,7 +541,7 @@ static void PS2_DestroyTexture(SDL_Renderer *renderer, SDL_Texture *texture)
     // Free from vram
     gsKit_TexManager_free(data->gsGlobal, ps2_texture);
 
-    SDL_free(ps2_texture->Mem);
+    SDL_aligned_free(ps2_texture->Mem);
     SDL_free(ps2_texture);
     texture->driverdata = NULL;
 }
diff --git a/src/video/ngage/SDL_ngagevideo.cpp b/src/video/ngage/SDL_ngagevideo.cpp
index 85f54bfc7..739b20106 100644
--- a/src/video/ngage/SDL_ngagevideo.cpp
+++ b/src/video/ngage/SDL_ngagevideo.cpp
@@ -67,7 +67,7 @@ static void NGAGE_DeleteDevice(SDL_VideoDevice *device)
             phdata->NGAGE_WsSession.RedrawReadyCancel();
         }
 
-        free(phdata->NGAGE_DrawDevice);
+        free(phdata->NGAGE_DrawDevice); /* This should NOT be SDL_free() */
 
         if (phdata->NGAGE_WsWindow.WsHandle()) {
             phdata->NGAGE_WsWindow.Close();
diff --git a/src/video/uikit/SDL_uikitappdelegate.m b/src/video/uikit/SDL_uikitappdelegate.m
index 716941a5b..4b93b8d2c 100644
--- a/src/video/uikit/SDL_uikitappdelegate.m
+++ b/src/video/uikit/SDL_uikitappdelegate.m
@@ -52,11 +52,15 @@ int SDL_RunApp(int argc, char* argv[], SDL_main_func mainFunction, void * reserv
     int i;
 
     /* store arguments */
+    /* Note that we need to be careful about how we allocate/free memory here.
+     * If the application calls SDL_SetMemoryFunctions(), we can't rely on
+     * SDL_free() to use the same allocator after SDL_main() returns.
+     */
     forward_main = mainFunction;
     forward_argc = argc;
-    forward_argv = (char **)malloc((argc + 1) * sizeof(char *));
+    forward_argv = (char **)malloc((argc + 1) * sizeof(char *)); /* This should NOT be SDL_malloc() */
     for (i = 0; i < argc; i++) {
-        forward_argv[i] = malloc((strlen(argv[i]) + 1) * sizeof(char));
+        forward_argv[i] = malloc((strlen(argv[i]) + 1) * sizeof(char)); /* This should NOT be SDL_malloc() */
         strcpy(forward_argv[i], argv[i]);
     }
     forward_argv[i] = NULL;
@@ -68,9 +72,9 @@ int SDL_RunApp(int argc, char* argv[], SDL_main_func mainFunction, void * reserv
 
     /* free the memory we used to hold copies of argc and argv */
     for (i = 0; i < forward_argc; i++) {
-        free(forward_argv[i]);
+        free(forward_argv[i]); /* This should NOT be SDL_free() */
     }
-    free(forward_argv);
+    free(forward_argv); /* This should NOT be SDL_free() */
 
     return exit_status;
 }