diff --git a/api.js b/api.js
index ebf272d3..f23d0d9d 100644
--- a/api.js
+++ b/api.js
@@ -467,7 +467,7 @@ module.exports = done => {
                   emit: (key, message) => log.info('Gelf', JSON.stringify(message))
               };
 
-    loggelf = message => {
+    loggelf = (message, requiredKeys = []) => {
         if (typeof message === 'string') {
             message = {
                 short_message: message
@@ -484,7 +484,8 @@ module.exports = done => {
         message.timestamp = Date.now() / 1000;
         message._component = component;
         Object.keys(message).forEach(key => {
-            if (!message[key]) {
+            if (!message[key] && !requiredKeys.includes(key)) {
+                // remove the key if it empty/falsy/undefined/null and it is not required to stay
                 delete message[key];
             }
         });
@@ -538,7 +539,7 @@ module.exports = done => {
 
     settingsHandler = new SettingsHandler({ db: db.database });
 
-    server.loggelf = message => loggelf(message);
+    server.loggelf = (message, requiredKeys = []) => loggelf(message, requiredKeys);
 
     server.lock = new Lock({
         redis: db.redis,
diff --git a/lib/api/users.js b/lib/api/users.js
index 5eb121eb..2536a505 100644
--- a/lib/api/users.js
+++ b/lib/api/users.js
@@ -1705,14 +1705,18 @@ module.exports = (db, server, userHandler, settingsHandler) => {
                 });
             }
 
-            server.loggelf({
-                short_message: '[QUOTA] reset',
-                _mail_action: 'quota',
-                _user: userData._id,
-                _set: Number(storageUsed) || 0,
-                _previous_storage_used: Number(updateResponse.value.storageUsed) || 0,
-                _storage_used: Number(storageUsed) || 0
-            });
+            server.loggelf(
+                {
+                    short_message: '[QUOTA] reset',
+                    _mail_action: 'quota',
+                    _user: userData._id,
+                    _set: Number(storageUsed) || 0,
+                    _previous_storage_used: Number(updateResponse.value.storageUsed) || 0,
+                    _storage_used: Number(storageUsed) || 0,
+                    _storage_diff: Math.abs((Number(updateResponse.value.storageUsed) || 0) - (Number(storageUsed) || 0))
+                },
+                ['_previous_storage_used', '_storage_used', '_storage_diff', '_set']
+            );
 
             return res.json({
                 success: true,