diff --git a/include/linux/zbud.h b/include/linux/zbud.h
index 2571a5c..13af0d4 100644
--- a/include/linux/zbud.h
+++ b/include/linux/zbud.h
@@ -11,7 +11,7 @@
 
 struct zbud_pool *zbud_create_pool(gfp_t gfp, struct zbud_ops *ops);
 void zbud_destroy_pool(struct zbud_pool *pool);
-int zbud_alloc(struct zbud_pool *pool, int size, gfp_t gfp,
+int zbud_alloc(struct zbud_pool *pool, unsigned int size, gfp_t gfp,
 	unsigned long *handle);
 void zbud_free(struct zbud_pool *pool, unsigned long handle);
 int zbud_reclaim_page(struct zbud_pool *pool, unsigned int retries);
diff --git a/mm/zbud.c b/mm/zbud.c
index 9451361..01df13a 100644
--- a/mm/zbud.c
+++ b/mm/zbud.c
@@ -247,7 +247,7 @@
  * gfp arguments are invalid or -ENOMEM if the pool was unable to allocate
  * a new page.
  */
-int zbud_alloc(struct zbud_pool *pool, int size, gfp_t gfp,
+int zbud_alloc(struct zbud_pool *pool, unsigned int size, gfp_t gfp,
 			unsigned long *handle)
 {
 	int chunks, i, freechunks;
@@ -255,7 +255,7 @@
 	enum buddy bud;
 	struct page *page;
 
-	if (size <= 0 || gfp & __GFP_HIGHMEM)
+	if (!size || (gfp & __GFP_HIGHMEM))
 		return -EINVAL;
 	if (size > PAGE_SIZE - ZHDR_SIZE_ALIGNED - CHUNK_SIZE)
 		return -ENOSPC;