diff --git a/service/ptos/ex/pool.c b/service/ptos/ex/pool.c
index 08e4ca0..dc696ad 100644
--- a/service/ptos/ex/pool.c
+++ b/service/ptos/ex/pool.c
@@ -132,7 +132,7 @@ PoolAllocateFromPage(USIZE Gran, POOL_PAGE *Page, USIZE ByteCount, PAGE_INFO *In
         return NULL;
     }
 
-    ChunksNeeded = ByteCount / Gran;
+    ChunksNeeded = ALIGN_UP(ByteCount, Gran) / Gran;
 
     /* Scan the page for free chunks */
     for (Idx = 0; Idx < sizeof(Page->Bitmap) * 8; ++Idx) {