diff --git a/timesketch/api/v1/resources.py b/timesketch/api/v1/resources.py
index 210f0d1968..fc181f3af0 100644
--- a/timesketch/api/v1/resources.py
+++ b/timesketch/api/v1/resources.py
@@ -2426,9 +2426,15 @@ def post(self, sketch_id):
                 'The user does not have write permission on the sketch.')
 
         for username in form.get('users', []):
-            base_username = username.split('@')[0]
-            base_username = base_username.strip()
-            user = User.query.filter_by(username=base_username).first()
+            # Try the username with any potential @domain preserved.
+            user = User.query.filter_by(username=username).first()
+
+            # If no hit, then try to strip the domain.
+            if not user:
+                base_username = username.split('@')[0]
+                base_username = base_username.strip()
+                user = User.query.filter_by(username=base_username).first()
+
             if user:
                 sketch.grant_permission(permission='read', user=user)
                 sketch.grant_permission(permission='write', user=user)