diff --git a/cache/disk/lru.go b/cache/disk/lru.go
index d806d91c6..d31ee61be 100644
--- a/cache/disk/lru.go
+++ b/cache/disk/lru.go
@@ -130,7 +130,7 @@ func (c *sizedLRU) MaxSize() int64 {
 }
 
 func (c *sizedLRU) Reserve(size int64) bool {
-	if size < 0 || size > c.maxSize || c.currentSize+size > c.maxSize {
+	if size < 0 || size > c.maxSize || c.reservedSize+size > c.maxSize {
 		return false
 	}