diff --git a/rm-server/source/java/org/alfresco/module/org_alfresco_module_rm/classification/ContentClassificationService.java b/rm-server/source/java/org/alfresco/module/org_alfresco_module_rm/classification/ContentClassificationService.java
index dc708c9164..227bac1c9e 100644
--- a/rm-server/source/java/org/alfresco/module/org_alfresco_module_rm/classification/ContentClassificationService.java
+++ b/rm-server/source/java/org/alfresco/module/org_alfresco_module_rm/classification/ContentClassificationService.java
@@ -50,6 +50,8 @@ public interface ContentClassificationService
      * @param classificationReasonIds A non-empty set of ids of reasons for classifying the content in this way.
      * @param content The node to classify.
      * @throws LevelIdNotFound If the supplied level id is not found.
+     * @thorws IllegalArgumentException If the supplied {@code classifiedBy} is {@code null},
+     *                                  the empty string or a string consisting only of whitespace.
      * @throws ReasonIdNotFound If any of the supplied reason ids are not found.
      * @throws InvalidNodeRefException If the node could not be found.
      * @throws InvalidNode If the supplied node is not a content node.
diff --git a/rm-server/source/java/org/alfresco/module/org_alfresco_module_rm/classification/ContentClassificationServiceImpl.java b/rm-server/source/java/org/alfresco/module/org_alfresco_module_rm/classification/ContentClassificationServiceImpl.java
index ccea4dd79a..612f6aaad6 100644
--- a/rm-server/source/java/org/alfresco/module/org_alfresco_module_rm/classification/ContentClassificationServiceImpl.java
+++ b/rm-server/source/java/org/alfresco/module/org_alfresco_module_rm/classification/ContentClassificationServiceImpl.java
@@ -89,7 +89,7 @@ public class ContentClassificationServiceImpl extends ServiceBaseImpl implements
                                 Set<String> classificationReasonIds, final NodeRef content)
     {
         checkNotBlank("classificationLevelId", classificationLevelId);
-        mandatory("classifiedBy", classifiedBy);
+        checkNotBlank("classifiedBy", classifiedBy);
         mandatory("classificationReasonIds", classificationReasonIds);
         mandatory("content", content);