diff --git a/processing/src/main/java/io/druid/query/extraction/JavascriptDimExtractionFn.java b/processing/src/main/java/io/druid/query/extraction/JavascriptDimExtractionFn.java
index d61d3b26b41fe384f99d1a3f9445e4a41d13a480..3935e07c2930e19f1b4c51f9cbb018dd40b6dbcc 100644
--- a/processing/src/main/java/io/druid/query/extraction/JavascriptDimExtractionFn.java
+++ b/processing/src/main/java/io/druid/query/extraction/JavascriptDimExtractionFn.java
@@ -98,4 +98,12 @@ public class JavascriptDimExtractionFn implements DimExtractionFn
   {
     return false;
   }
+
+  @Override
+  public String toString()
+  {
+    return "JavascriptDimExtractionFn{" +
+           "function='" + function + '\'' +
+           '}';
+  }
 }