diff --git a/ovsdb/rfc/src/main/java/org/onosproject/ovsdb/rfc/operations/Comment.java b/ovsdb/rfc/src/main/java/org/onosproject/ovsdb/rfc/operations/Comment.java
index c27de6b..2853e1f 100644
--- a/ovsdb/rfc/src/main/java/org/onosproject/ovsdb/rfc/operations/Comment.java
+++ b/ovsdb/rfc/src/main/java/org/onosproject/ovsdb/rfc/operations/Comment.java
@@ -32,7 +32,7 @@
      * @param comment the comment member of comment operation
      */
     public Comment(String comment) {
-        checkNotNull(comment, "comment is not null");
+        checkNotNull(comment, "comment cannot be null");
         this.op = Operations.COMMENT.op();
         this.comment = comment;
     }