diff --git a/docs/README-migration.md b/docs/README-migration.md
index 48a2a73abb..29a5bbce63 100644
--- a/docs/README-migration.md
+++ b/docs/README-migration.md
@@ -920,7 +920,7 @@ The functions SDL_GetJoysticks(), SDL_GetJoystickNameForID(), SDL_GetJoystickPat
 
 SDL_AttachVirtualJoystick() now returns the joystick instance ID instead of a device index, and returns 0 if there was an error.
 
-SDL_VirtualJoystickDesc no longer takes a struct version; if we need to extend this in the future, we'll make a second struct and a second SDL_AttachVirtualJoystickEx-style function that uses it. Just zero the struct and don't set a version.
+SDL_VirtualJoystickDesc version should not be set to SDL_VIRTUAL_JOYSTICK_DESC_VERSION, instead the structure should be initialized using SDL_INIT_INTERFACE().
 
 The following functions have been renamed:
 * SDL_JoystickAttachVirtualEx() => SDL_AttachVirtualJoystick()
@@ -983,7 +983,7 @@ The following functions have been removed:
 * SDL_JoystickNameForIndex() - replaced with SDL_GetJoystickNameForID()
 * SDL_JoystickPathForIndex() - replaced with SDL_GetJoystickPathForID()
 * SDL_NumJoysticks() - replaced with SDL_GetJoysticks()
-* SDL_VIRTUAL_JOYSTICK_DESC_VERSION - no longer needed, version info has been removed from SDL_VirtualJoystickDesc.
+* SDL_VIRTUAL_JOYSTICK_DESC_VERSION - no longer needed
 
 The following symbols have been removed:
 * SDL_JOYBALLMOTION
@@ -1568,7 +1568,7 @@ SDL_IOStream *SDL_RWFromFP(FILE *fp, SDL_bool autoclose)
         return NULL;
     }
 
-    SDL_zero(iface);
+    SDL_INIT_INTERFACE(&iface);
     /* There's no stdio_size because SDL_GetIOSize emulates it the same way we'd do it for stdio anyhow. */
     iface.seek = stdio_seek;
     iface.read = stdio_read;
diff --git a/include/SDL3/SDL_iostream.h b/include/SDL3/SDL_iostream.h
index 4e4ea1294d..b82116ddc8 100644
--- a/include/SDL3/SDL_iostream.h
+++ b/include/SDL3/SDL_iostream.h
@@ -83,10 +83,17 @@ typedef enum SDL_IOWhence
  * already offers several common types of I/O streams, via functions like
  * SDL_IOFromFile() and SDL_IOFromMem().
  *
+ * This structure should be initialized using SDL_INIT_INTERFACE()
+ *
  * \since This struct is available since SDL 3.0.0.
+ *
+ * \sa SDL_INIT_INTERFACE
  */
 typedef struct SDL_IOStreamInterface
 {
+    /* The version of this interface */
+    Uint32 version;
+
     /**
      *  Return the number of bytes in this SDL_IOStream
      *
@@ -138,6 +145,15 @@ typedef struct SDL_IOStreamInterface
 
 } SDL_IOStreamInterface;
 
+/* Check the size of SDL_IOStreamInterface
+ *
+ * If this assert fails, either the compiler is padding to an unexpected size,
+ * or the interface has been updated and this should be updated to match and
+ * the code using this interface should be updated to handle the old version.
+ */
+SDL_COMPILE_TIME_ASSERT(SDL_IOStreamInterface_SIZE,
+    (sizeof(void *) == 4 && sizeof(SDL_IOStreamInterface) == 24) ||
+    (sizeof(void *) == 8 && sizeof(SDL_IOStreamInterface) == 48));
 
 /**
  * The read/write operation structure.
@@ -347,20 +363,18 @@ extern SDL_DECLSPEC SDL_IOStream * SDLCALL SDL_IOFromDynamicMem(void);
  * read/write a common data source, you should use the built-in
  * implementations in SDL, like SDL_IOFromFile() or SDL_IOFromMem(), etc.
  *
- * You must free the returned pointer with SDL_CloseIO().
- *
  * This function makes a copy of `iface` and the caller does not need to keep
- * this data around after this call.
+ * it around after this call.
  *
- * \param iface the function pointers that implement this SDL_IOStream.
- * \param userdata the app-controlled pointer that is passed to iface's
- *                 functions when called.
+ * \param iface the interface that implements this SDL_IOStream, initialized using SDL_INIT_INTERFACE().
+ * \param userdata the pointer that will be passed to the interface functions.
  * \returns a pointer to the allocated memory on success or NULL on failure;
  *          call SDL_GetError() for more information.
  *
  * \since This function is available since SDL 3.0.0.
  *
  * \sa SDL_CloseIO
+ * \sa SDL_INIT_INTERFACE
  * \sa SDL_IOFromConstMem
  * \sa SDL_IOFromFile
  * \sa SDL_IOFromMem
diff --git a/include/SDL3/SDL_joystick.h b/include/SDL3/SDL_joystick.h
index 43bc1e98f7..da28a24460 100644
--- a/include/SDL3/SDL_joystick.h
+++ b/include/SDL3/SDL_joystick.h
@@ -414,16 +414,18 @@ typedef struct SDL_VirtualJoystickSensorDesc
 /**
  * The structure that describes a virtual joystick.
  *
- * All elements of this structure are optional and can be left 0.
+ * This structure should be initialized using SDL_INIT_INTERFACE(). All elements of this structure are optional.
  *
  * \since This struct is available since SDL 3.0.0.
  *
  * \sa SDL_AttachVirtualJoystick
+ * \sa SDL_INIT_INTERFACE
  * \sa SDL_VirtualJoystickSensorDesc
  * \sa SDL_VirtualJoystickTouchpadDesc
  */
 typedef struct SDL_VirtualJoystickDesc
 {
+    Uint32 version;     /**< the version of this interface */
     Uint16 type;        /**< `SDL_JoystickType` */
     Uint16 padding;     /**< unused */
     Uint16 vendor_id;   /**< the USB vendor ID of this joystick */
@@ -454,10 +456,20 @@ typedef struct SDL_VirtualJoystickDesc
     void (SDLCALL *Cleanup)(void *userdata); /**< Cleans up the userdata when the joystick is detached */
 } SDL_VirtualJoystickDesc;
 
+/* Check the size of SDL_VirtualJoystickDesc
+ *
+ * If this assert fails, either the compiler is padding to an unexpected size,
+ * or the interface has been updated and this should be updated to match and
+ * the code using this interface should be updated to handle the old version.
+ */
+SDL_COMPILE_TIME_ASSERT(SDL_VirtualJoystickDesc_SIZE,
+    (sizeof(void *) == 4 && sizeof(SDL_VirtualJoystickDesc) == 84) ||
+    (sizeof(void *) == 8 && sizeof(SDL_VirtualJoystickDesc) == 136));
+
 /**
  * Attach a new virtual joystick.
  *
- * \param desc joystick description.
+ * \param desc joystick description, initialized using SDL_INIT_INTERFACE().
  * \returns the joystick instance ID, or 0 on failure; call SDL_GetError() for
  *          more information.
  *
diff --git a/include/SDL3/SDL_stdinc.h b/include/SDL3/SDL_stdinc.h
index dd9f7b5df0..9ae20d7c97 100644
--- a/include/SDL3/SDL_stdinc.h
+++ b/include/SDL3/SDL_stdinc.h
@@ -529,6 +529,49 @@ SDL_COMPILE_TIME_ASSERT(enum, sizeof(SDL_DUMMY_ENUM) == sizeof(int));
 extern "C" {
 #endif
 
+/**
+ * A macro to initialize an SDL interface.
+ *
+ * This macro will initialize an SDL interface structure and should be called before you fill out the fields with your implementation.
+ *
+ * You can use it like this:
+ *
+ * ```c
+ * SDL_IOStreamInterface iface;
+ *
+ * SDL_INIT_INTERFACE(&iface);
+ *
+ * // Fill in the interface function pointers with your implementation
+ * iface.seek = ...
+ *
+ * stream = SDL_OpenIO(&iface, NULL);
+ * ```
+ *
+ * If you are using designated initializers, you can use the size of the interface as the version, e.g.
+ *
+ * ```c
+ * SDL_IOStreamInterface iface = {
+ *     .version = sizeof(iface),
+ *     .seek = ...
+ * };
+ * stream = SDL_OpenIO(&iface, NULL);
+ * ```
+ *
+ * \threadsafety It is safe to call this macro from any thread.
+ *
+ * \since This macro is available since SDL 3.0.0.
+ *
+ * \sa SDL_IOStreamInterface
+ * \sa SDL_StorageInterface
+ * \sa SDL_VirtualJoystickDesc
+ */
+#define SDL_INIT_INTERFACE(iface)               \
+    do {                                        \
+        SDL_zerop(iface);                       \
+        (iface)->version = sizeof(*(iface));    \
+    } while (0)
+
+
 #ifndef SDL_DISABLE_ALLOCA
 #define SDL_stack_alloc(type, count)    (type*)alloca(sizeof(type)*(count))
 #define SDL_stack_free(data)
diff --git a/include/SDL3/SDL_storage.h b/include/SDL3/SDL_storage.h
index 91a90bc4ee..d965cfd516 100644
--- a/include/SDL3/SDL_storage.h
+++ b/include/SDL3/SDL_storage.h
@@ -52,10 +52,17 @@ extern "C" {
  * It is not usually necessary to do this; SDL provides standard
  * implementations for many things you might expect to do with an SDL_Storage.
  *
+ * This structure should be initialized using SDL_INIT_INTERFACE()
+ *
  * \since This struct is available since SDL 3.0.0.
+ *
+ * \sa SDL_INIT_INTERFACE
  */
 typedef struct SDL_StorageInterface
 {
+    /* The version of this interface */
+    Uint32 version;
+
     /* Called when the storage is closed */
     SDL_bool (SDLCALL *close)(void *userdata);
 
@@ -90,6 +97,15 @@ typedef struct SDL_StorageInterface
     Uint64 (SDLCALL *space_remaining)(void *userdata);
 } SDL_StorageInterface;
 
+/* Check the size of SDL_StorageInterface
+ *
+ * If this assert fails, either the compiler is padding to an unexpected size,
+ * or the interface has been updated and this should be updated to match and
+ * the code using this interface should be updated to handle the old version.
+ */
+SDL_COMPILE_TIME_ASSERT(SDL_StorageInterface_SIZE,
+    (sizeof(void *) == 4 && sizeof(SDL_StorageInterface) == 48) ||
+    (sizeof(void *) == 8 && sizeof(SDL_StorageInterface) == 96));
 /**
  * An abstract interface for filesystem access.
  *
@@ -176,8 +192,11 @@ extern SDL_DECLSPEC SDL_Storage * SDLCALL SDL_OpenFileStorage(const char *path);
  * should use the built-in implementations in SDL, like SDL_OpenTitleStorage()
  * or SDL_OpenUserStorage().
  *
- * \param iface the function table to be used by this container.
- * \param userdata the pointer that will be passed to the store interface.
+ * This function makes a copy of `iface` and the caller does not need to keep
+ * it around after this call.
+ *
+ * \param iface the interface that implements this storage, initialized using SDL_INIT_INTERFACE().
+ * \param userdata the pointer that will be passed to the interface functions.
  * \returns a storage container on success or NULL on failure; call
  *          SDL_GetError() for more information.
  *
@@ -186,6 +205,7 @@ extern SDL_DECLSPEC SDL_Storage * SDLCALL SDL_OpenFileStorage(const char *path);
  * \sa SDL_CloseStorage
  * \sa SDL_GetStorageFileSize
  * \sa SDL_GetStorageSpaceRemaining
+ * \sa SDL_INIT_INTERFACE
  * \sa SDL_ReadStorageFile
  * \sa SDL_StorageReady
  * \sa SDL_WriteStorageFile
diff --git a/src/file/SDL_iostream.c b/src/file/SDL_iostream.c
index 7c04e65a68..59cb472259 100644
--- a/src/file/SDL_iostream.c
+++ b/src/file/SDL_iostream.c
@@ -419,7 +419,7 @@ static SDL_IOStream *SDL_IOFromFP(FILE *fp, bool autoclose)
     }
 
     SDL_IOStreamInterface iface;
-    SDL_zero(iface);
+    SDL_INIT_INTERFACE(&iface);
     // There's no stdio_size because SDL_GetIOSize emulates it the same way we'd do it for stdio anyhow.
     iface.seek = stdio_seek;
     iface.read = stdio_read;
@@ -607,7 +607,7 @@ SDL_IOStream *SDL_IOFromFile(const char *file, const char *mode)
     }
 
     SDL_IOStreamInterface iface;
-    SDL_zero(iface);
+    SDL_INIT_INTERFACE(&iface);
     iface.size = Android_JNI_FileSize;
     iface.seek = Android_JNI_FileSeek;
     iface.read = Android_JNI_FileRead;
@@ -636,7 +636,7 @@ SDL_IOStream *SDL_IOFromFile(const char *file, const char *mode)
     }
 
     SDL_IOStreamInterface iface;
-    SDL_zero(iface);
+    SDL_INIT_INTERFACE(&iface);
     iface.size = windows_file_size;
     iface.seek = windows_file_seek;
     iface.read = windows_file_read;
@@ -698,7 +698,7 @@ SDL_IOStream *SDL_IOFromMem(void *mem, size_t size)
     }
 
     SDL_IOStreamInterface iface;
-    SDL_zero(iface);
+    SDL_INIT_INTERFACE(&iface);
     iface.size = mem_size;
     iface.seek = mem_seek;
     iface.read = mem_read;
@@ -732,7 +732,7 @@ SDL_IOStream *SDL_IOFromConstMem(const void *mem, size_t size)
     }
 
     SDL_IOStreamInterface iface;
-    SDL_zero(iface);
+    SDL_INIT_INTERFACE(&iface);
     iface.size = mem_size;
     iface.seek = mem_seek;
     iface.read = mem_read;
@@ -832,7 +832,7 @@ SDL_IOStream *SDL_IOFromDynamicMem(void)
     }
 
     SDL_IOStreamInterface iface;
-    SDL_zero(iface);
+    SDL_INIT_INTERFACE(&iface);
     iface.size = dynamic_mem_size;
     iface.seek = dynamic_mem_seek;
     iface.read = dynamic_mem_read;
@@ -868,6 +868,11 @@ SDL_IOStream *SDL_OpenIO(const SDL_IOStreamInterface *iface, void *userdata)
         SDL_InvalidParamError("iface");
         return NULL;
     }
+    if (iface->version < sizeof(*iface)) {
+        // Update this to handle older versions of this interface
+        SDL_SetError("Invalid interface, should be initialized with SDL_INIT_INTERFACE()");
+        return NULL;
+    }
 
     SDL_IOStream *iostr = (SDL_IOStream *)SDL_calloc(1, sizeof(*iostr));
     if (iostr) {
diff --git a/src/joystick/virtual/SDL_virtualjoystick.c b/src/joystick/virtual/SDL_virtualjoystick.c
index 0bbb0b51f6..bc3ef3f272 100644
--- a/src/joystick/virtual/SDL_virtualjoystick.c
+++ b/src/joystick/virtual/SDL_virtualjoystick.c
@@ -142,6 +142,11 @@ SDL_JoystickID SDL_JoystickAttachVirtualInner(const SDL_VirtualJoystickDesc *des
         SDL_InvalidParamError("desc");
         return 0;
     }
+    if (desc->version < sizeof(*desc)) {
+        // Update this to handle older versions of this interface
+        SDL_SetError("Invalid desc, should be initialized with SDL_INIT_INTERFACE()");
+        return 0;
+    }
 
     hwdata = (joystick_hwdata *)SDL_calloc(1, sizeof(joystick_hwdata));
     if (!hwdata) {
diff --git a/src/storage/SDL_storage.c b/src/storage/SDL_storage.c
index 5f8fb336c2..069d9af799 100644
--- a/src/storage/SDL_storage.c
+++ b/src/storage/SDL_storage.c
@@ -153,6 +153,11 @@ SDL_Storage *SDL_OpenStorage(const SDL_StorageInterface *iface, void *userdata)
         SDL_InvalidParamError("iface");
         return NULL;
     }
+    if (iface->version < sizeof(*iface)) {
+        // Update this to handle older versions of this interface
+        SDL_SetError("Invalid interface, should be initialized with SDL_INIT_INTERFACE()");
+        return NULL;
+    }
 
     storage = (SDL_Storage *)SDL_calloc(1, sizeof(*storage));
     if (storage) {
diff --git a/src/storage/generic/SDL_genericstorage.c b/src/storage/generic/SDL_genericstorage.c
index 430b93df2f..4cd856cef7 100644
--- a/src/storage/generic/SDL_genericstorage.c
+++ b/src/storage/generic/SDL_genericstorage.c
@@ -182,6 +182,7 @@ static Uint64 GENERIC_GetStorageSpaceRemaining(void *userdata)
 }
 
 static const SDL_StorageInterface GENERIC_title_iface = {
+    sizeof(SDL_StorageInterface),
     GENERIC_CloseStorage,
     NULL,   // ready
     GENERIC_EnumerateStorageDirectory,
@@ -224,6 +225,7 @@ TitleStorageBootStrap GENERIC_titlebootstrap = {
 };
 
 static const SDL_StorageInterface GENERIC_user_iface = {
+    sizeof(SDL_StorageInterface),
     GENERIC_CloseStorage,
     NULL,   // ready
     GENERIC_EnumerateStorageDirectory,
@@ -259,6 +261,7 @@ UserStorageBootStrap GENERIC_userbootstrap = {
 };
 
 static const SDL_StorageInterface GENERIC_file_iface = {
+    sizeof(SDL_StorageInterface),
     GENERIC_CloseStorage,
     NULL,   // ready
     GENERIC_EnumerateStorageDirectory,
diff --git a/src/storage/steam/SDL_steamstorage.c b/src/storage/steam/SDL_steamstorage.c
index 237334e2e9..7977ca71ab 100644
--- a/src/storage/steam/SDL_steamstorage.c
+++ b/src/storage/steam/SDL_steamstorage.c
@@ -129,6 +129,7 @@ static Uint64 STEAM_GetStorageSpaceRemaining(void *userdata)
 }
 
 static const SDL_StorageInterface STEAM_user_iface = {
+    sizeof(SDL_StorageInterface),
     STEAM_CloseStorage,
     STEAM_StorageReady,
     NULL,   // enumerate
diff --git a/test/testautomation_iostream.c b/test/testautomation_iostream.c
index 782d643b04..7a5a23d2ec 100644
--- a/test/testautomation_iostream.c
+++ b/test/testautomation_iostream.c
@@ -437,7 +437,7 @@ static int iostrm_testAllocFree(void *arg)
     SDL_IOStreamInterface iface;
     SDL_IOStream *rw;
 
-    SDL_zero(iface);
+    SDL_INIT_INTERFACE(&iface);
     rw = SDL_OpenIO(&iface, NULL);
     SDLTest_AssertPass("Call to SDL_OpenIO() succeeded");
     SDLTest_AssertCheck(rw != NULL, "Validate result from SDL_OpenIO() is not NULL");
diff --git a/test/testautomation_joystick.c b/test/testautomation_joystick.c
index a7778e526f..ca4baebbfd 100644
--- a/test/testautomation_joystick.c
+++ b/test/testautomation_joystick.c
@@ -27,7 +27,7 @@ static int TestVirtualJoystick(void *arg)
 
     SDL_SetHint(SDL_HINT_JOYSTICK_ALLOW_BACKGROUND_EVENTS, "1");
 
-    SDL_zero(desc);
+    SDL_INIT_INTERFACE(&desc);
     desc.type = SDL_JOYSTICK_TYPE_GAMEPAD;
     desc.naxes = SDL_GAMEPAD_AXIS_MAX;
     desc.nbuttons = SDL_GAMEPAD_BUTTON_MAX;
diff --git a/test/testcontroller.c b/test/testcontroller.c
index 2da043ae1f..91400b913b 100644
--- a/test/testcontroller.c
+++ b/test/testcontroller.c
@@ -1159,7 +1159,7 @@ static void OpenVirtualGamepad(void)
         return;
     }
 
-    SDL_zero(desc);
+    SDL_INIT_INTERFACE(&desc);
     desc.type = SDL_JOYSTICK_TYPE_GAMEPAD;
     desc.naxes = SDL_GAMEPAD_AXIS_MAX;
     desc.nbuttons = SDL_GAMEPAD_BUTTON_MAX;