diff --git a/public/scripts/templates/deleteUser.html b/public/scripts/templates/deleteUser.html
index 35f4cd1fc..6932f3b99 100644
--- a/public/scripts/templates/deleteUser.html
+++ b/public/scripts/templates/deleteUser.html
@@ -16,9 +16,11 @@
         <span data-i18n="This action is irreversible.">This action is irreversible.</span>
     </div>
     <div>
-        <label for="deleteUserHandle" data-i18n="Type the user's handle below to confirm:">
-            Type the user's handle below to confirm:
+        <label for="deleteUserHandle">
+            <strong data-i18n="Type the user's handle below to confirm:">
+                Type the user's handle below to confirm:
+            </strong>
         </label>
-        <input id="deleteUserHandle" name="deleteUserHandle" type="text" class="text_pole" placeholder="">
+        <input id="deleteUserHandle" name="deleteUserHandle" type="text" class="text_pole" placeholder="[ Type here ]">
     </div>
 </div>
diff --git a/src/constants.js b/src/constants.js
index 2c5bd5e7d..929e7e7cd 100644
--- a/src/constants.js
+++ b/src/constants.js
@@ -50,7 +50,7 @@ const DEFAULT_USER = Object.freeze({
     uuid: '00000000-0000-0000-0000-000000000000',
     handle: 'user0',
     name: 'User',
-    created: 0,
+    created: Date.now(),
     password: '',
     admin: true,
     enabled: true,
diff --git a/src/endpoints/users-admin.js b/src/endpoints/users-admin.js
index e3e45afe2..764f5263e 100644
--- a/src/endpoints/users-admin.js
+++ b/src/endpoints/users-admin.js
@@ -157,7 +157,12 @@ router.post('/create', requireAdminMiddleware, jsonParser, async (request, respo
         }
 
         const handles = await getAllUserHandles();
-        const handle = slugify(request.body.handle, { lower: true, trim: true });
+        const handle = slugify(request.body.handle, { lower: true, trim: true, remove: /[^a-z0-9-]/g });
+
+        if (!handle) {
+            console.log('Create user failed: Invalid handle');
+            return response.status(400).json({ error: 'Invalid handle' });
+        }
 
         if (handles.some(x => x === handle)) {
             console.log('Create user failed: User with that handle already exists');