diff --git a/common/src/main/java/io/netty/util/collection/IntObjectHashMap.java b/common/src/main/java/io/netty/util/collection/IntObjectHashMap.java
index 4d1cdfc78f..1a4d019e56 100644
--- a/common/src/main/java/io/netty/util/collection/IntObjectHashMap.java
+++ b/common/src/main/java/io/netty/util/collection/IntObjectHashMap.java
@@ -311,11 +311,9 @@ public class IntObjectHashMap<V> implements IntObjectMap<V>, Iterable<IntObjectM
      * Returns the hashed index for the given key.
      */
     private int hashIndex(int key) {
-        int hash = key % keys.length;
-        if (hash < 0) {
-            hash += keys.length;
-        }
-        return hash;
+        int length = keys.length;
+        // Allowing for negative keys by adding the length after the first mod operation.
+        return (key % length + length) % length;
     }
 
     /**