diff --git a/src/main/java/org/codehaus/groovy/util/ListHashMap.java b/src/main/java/org/codehaus/groovy/util/ListHashMap.java
index 5063295ff91..15845ed5f05 100644
--- a/src/main/java/org/codehaus/groovy/util/ListHashMap.java
+++ b/src/main/java/org/codehaus/groovy/util/ListHashMap.java
@@ -20,6 +20,7 @@
 
 import java.util.Collection;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.Map;
 import java.util.Set;
 
@@ -200,7 +201,7 @@ public int size() {
     }
 
     private Map<K,V> toMap() {
-        Map<K,V> m = new java.util.HashMap<>();
+        Map<K,V> m = new HashMap<>((int) (size / 0.75) + 1);
         for (int i = 0; i < size; i += 1) {
             m.put(keys[i], values[i]);
         }