1 files changed, 12 insertions, 1 deletions
diff --git a/container-search/src/main/java/com/yahoo/search/grouping/request/StringValue.java b/container-search/src/main/java/com/yahoo/search/grouping/request/StringValue.java
index 4fc630c7b1b..473e6b73f95 100644
--- a/container-search/src/main/java/com/yahoo/search/grouping/request/StringValue.java
+++ b/container-search/src/main/java/com/yahoo/search/grouping/request/StringValue.java
@@ -5,6 +5,7 @@ package com.yahoo.search.grouping.request;
  * This class represents a constant {@link String} value in a {@link GroupingExpression}.
  *
  * @author Simon Thoresen Hult
+ * @author bratseth
  */
 public class StringValue extends ConstantValue<String> {
 
@@ -14,6 +15,16 @@ public class StringValue extends ConstantValue<String> {
      * @param value The immutable value to assign to this.
      */
     public StringValue(String value) {
-        super(value);
+        super(null, null, value);
     }
+
+    private StringValue(String label, Integer level, String value) {
+        super(label, level, value);
+    }
+
+    @Override
+    public StringValue copy() {
+        return new StringValue(getLabel(), getLevelOrNull(), getValue());
+    }
+
 }