diff --git a/include/private/vkd3d_memory.h b/include/private/vkd3d_memory.h
index e191dc11..b157fc07 100644
--- a/include/private/vkd3d_memory.h
+++ b/include/private/vkd3d_memory.h
@@ -43,7 +43,7 @@ static inline void *vkd3d_realloc(void *ptr, size_t size)
 static inline void *vkd3d_calloc(size_t count, size_t size)
 {
     void *ptr;
-    VKD3D_ASSERT(count <= ~(size_t)0 / size);
+    VKD3D_ASSERT(!size || count <= ~(size_t)0 / size);
     if (!(ptr = calloc(count, size)))
         ERR("Out of memory.\n");
     return ptr;