diff --git a/articles/minimum-stack.md b/articles/minimum-stack.md
index e1d8d261c..dfb5c9b57 100644
--- a/articles/minimum-stack.md
+++ b/articles/minimum-stack.md
@@ -457,8 +457,8 @@ public class MinStack {
 
     public void pop() {
         if (stack.isEmpty()) return;
-        int top = stack.pop();
-        if (top == minStack.peek()) {
+        Integer top = stack.pop();
+        if (top.equals(minStack.peek())) {
             minStack.pop();
         }
     }