diff --git a/src/apps.js b/src/apps.js
index a71a0f24a..139901e29 100644
--- a/src/apps.js
+++ b/src/apps.js
@@ -84,7 +84,7 @@ function AppsError(reason, errorOrMessage) {
 
     this.name = this.constructor.name;
     this.reason = reason;
-    if (typeof errorOrMessage === 'undefined' || errorOrMessage === null) {
+    if (typeof errorOrMessage === 'undefined') {
         this.message = reason;
     } else if (typeof errorOrMessage === 'string') {
         this.message = errorOrMessage;
diff --git a/src/databaseerror.js b/src/databaseerror.js
index f436cb592..a63b5db3a 100644
--- a/src/databaseerror.js
+++ b/src/databaseerror.js
@@ -16,7 +16,7 @@ function DatabaseError(reason, errorOrMessage) {
 
     this.name = this.constructor.name;
     this.reason = reason;
-    if (typeof errorOrMessage === 'undefined' || errorOrMessage === null) {
+    if (typeof errorOrMessage === 'undefined') {
         this.message = reason;
     } else if (typeof errorOrMessage === 'string') {
         this.message = errorOrMessage;
diff --git a/src/userdb.js b/src/userdb.js
index a8488c474..075bf843a 100644
--- a/src/userdb.js
+++ b/src/userdb.js
@@ -171,7 +171,7 @@ function del(userId, callback) {
     database.transaction(queries, function (error, result) {
         if (error && error.code === 'ER_NO_REFERENCED_ROW_2') return callback(new DatabaseError(DatabaseError.NOT_FOUND, error));
         if (error) return callback(new DatabaseError(DatabaseError.INTERNAL_ERROR, error));
-        if (result[1].affectedRows !== 1) return callback(new DatabaseError(DatabaseError.NOT_FOUND, error));
+        if (result[1].affectedRows !== 1) return callback(new DatabaseError(DatabaseError.NOT_FOUND));
 
         callback(error);
     });