diff --git a/src/gpu/xr/SDL_gpu_openxr.c b/src/gpu/xr/SDL_gpu_openxr.c
index 1404f1260c..e4104365d1 100644
--- a/src/gpu/xr/SDL_gpu_openxr.c
+++ b/src/gpu/xr/SDL_gpu_openxr.c
@@ -128,7 +128,9 @@ XrResult SDL_OPENXR_INTERNAL_GPUInitOpenXR(
 #endif
 
     const char **extensionNames = SDL_stack_alloc(const char *, userExtensionCount + platformExtensionCount);
-    SDL_memcpy((void *)extensionNames, userExtensionNames, sizeof(const char *) * (userExtensionCount));
+    if (userExtensionCount > 0) {
+        SDL_memcpy((void *)extensionNames, userExtensionNames, sizeof(const char *) * userExtensionCount);
+    }
     extensionNames[userExtensionCount] = gpuExtension.extensionName;
 #ifdef SDL_PLATFORM_ANDROID
     extensionNames[userExtensionCount + 1] = XR_KHR_ANDROID_CREATE_INSTANCE_EXTENSION_NAME;