diff --git a/frappe/commands/site.py b/frappe/commands/site.py
index 832364ab92..bb7d8a3084 100644
--- a/frappe/commands/site.py
+++ b/frappe/commands/site.py
@@ -1206,6 +1206,10 @@ def browse(context, site, user=None):
 
 	sid = ""
 	if user:
+		if not frappe.db.exists("User", user):
+			click.echo(f"User {user} does not exist")
+			sys.exit(1)
+
 		if frappe.conf.developer_mode or user == "Administrator":
 			frappe.utils.set_request(path="/")
 			frappe.local.cookie_manager = CookieManager()