diff --git a/src/app/user/controllers/UserController.php b/src/app/user/controllers/UserController.php
index 054403c93283e2e3540ff0f7c486f0a267360b1c..5cccdbbe10c3a62167f74a14b46f9e762e143185 100755
--- a/src/app/user/controllers/UserController.php
+++ b/src/app/user/controllers/UserController.php
@@ -483,6 +483,8 @@ class UserController
             return $response->withStatus(400)->withJson(['errors' => 'Body notifications.instant is not a boolean']);
         } elseif (!Validator::arrayType()->each(Validator::in($notificationsIds))->validate($body['notifications']['summaries'])) {
             return $response->withStatus(400)->withJson(['errors' => 'Body notifications.summaries is not an array or contains invalid IDs']);
+        } elseif (!Validator::oneOf(Validator::falseVal(), Validator::intVal()->between(10, 50))->validate($body['signatureScaling'])) {
+            return $response->withStatus(400)->withJson(['errors' => 'Body signatureScaling is neither false nor an integer between 10 and 50']);
         }
 
         $user = UserModel::getById(['id' => $args['id'], 'select' => ['firstname', 'lastname']]);
@@ -492,14 +494,15 @@ class UserController
 
         $body['notifications']['summaries'] = array_values(array_unique($body['notifications']['summaries']));
         $preferences = json_encode([
-            'lang'          => $body['lang'],
-            'writingMode'   => $body['writingMode'],
-            'writingSize'   => $body['writingSize'],
-            'writingColor'  => $body['writingColor'],
-            'notifications' => [
-                'instant'   => $body['notifications']['instant'],
-                'summaries' => $body['notifications']['summaries'],
-            ],
+            'lang'             => $body['lang'],
+            'writingMode'      => $body['writingMode'],
+            'writingSize'      => $body['writingSize'],
+            'writingColor'     => $body['writingColor'],
+            'signatureScaling' => $body['signatureScaling'],
+            'notifications'    => [
+                'instant'      => $body['notifications']['instant'],
+                'summaries'    => $body['notifications']['summaries'],
+            ]
         ]);
         if (!is_string($preferences)) {
             return $response->withStatus(400)->withJson(['errors' => 'Wrong format for user preferences data']);