diff --git a/src/main/java/us/monoid/json/JSONObject.java b/src/main/java/us/monoid/json/JSONObject.java
index a8f00e9..7bc51c2 100644
--- a/src/main/java/us/monoid/json/JSONObject.java
+++ b/src/main/java/us/monoid/json/JSONObject.java
@@ -1903,7 +1903,7 @@ String toString(int indentFactor, int indent) throws JSONException {
 	 *           If the value is or contains an invalid number.
 	 */
 	static String valueToString(Object value) throws JSONException {
-		if (value == null || value.equals(null)) {
+		if (value == null || value.equals("null")) {
 			return "null";
 		}
 		if (value instanceof JSONString) {
@@ -1955,7 +1955,7 @@ static String valueToString(Object value) throws JSONException {
 	 *           If the object contains an invalid number.
 	 */
 	static String valueToString(Object value, int indentFactor, int indent) throws JSONException {
-		if (value == null || value.equals(null)) {
+		if (value == null || value.equals("null")) {
 			return "null";
 		}
 		try {