diff --git a/lib/redis-util.js b/lib/redis-util.js
index 2745d47..945ab7a 100644
--- a/lib/redis-util.js
+++ b/lib/redis-util.js
@@ -146,7 +146,6 @@ const decrement = (product, xid) => new Promise((resolve) => {
         resolve(reply);
     });
 });
-exports.decrement = decrement;
 
 const increment = (product, xid) => new Promise((resolve) => {
     const keyword = composeKeyword(product);
@@ -202,7 +201,7 @@ const dispose = async (product, xid) => {
         return 0;
     }
 
-    return remaining;
+    return remaining + 1;
 };
 exports.dispose = dispose;