diff --git a/src/main/java/algorithms/sprint2/Deque.java b/src/main/java/algorithms/sprint2/Deque.java
index c3f3141..408d102 100644
--- a/src/main/java/algorithms/sprint2/Deque.java
+++ b/src/main/java/algorithms/sprint2/Deque.java
@@ -68,11 +68,13 @@ static final class RingDeque {
         }
 
         private int next(int i) {
-            return (i+1) % cap;
+            i++;
+            return i == cap ? 0 : i;
         }
 
         private int prev(int i) {
-            return (i-1+cap) % cap;
+            i--;
+            return i == -1 ? cap - 1 : i;
         }
 
         boolean isEmpty() {