diff --git a/ovsdb/rfc/src/main/java/org/onosproject/ovsdb/rfc/schema/type/KeyValuedColumnType.java b/ovsdb/rfc/src/main/java/org/onosproject/ovsdb/rfc/schema/type/KeyValuedColumnType.java
index 2419cdd..8407457 100644
--- a/ovsdb/rfc/src/main/java/org/onosproject/ovsdb/rfc/schema/type/KeyValuedColumnType.java
+++ b/ovsdb/rfc/src/main/java/org/onosproject/ovsdb/rfc/schema/type/KeyValuedColumnType.java
@@ -39,8 +39,8 @@
      */
     public KeyValuedColumnType(BaseType keyType, BaseType valueType, int min,
                                int max) {
-        checkNotNull(keyType, "keyType is not null");
-        checkNotNull(valueType, "valueType is not null");
+        checkNotNull(keyType, "keyType cannot be null");
+        checkNotNull(valueType, "valueType cannot be null");
         this.keyType = keyType;
         this.valueType = valueType;
         this.min = min;