diff --git a/litestar/security/jwt/middleware.py b/litestar/security/jwt/middleware.py
index 305f4011a3..cad5925371 100644
--- a/litestar/security/jwt/middleware.py
+++ b/litestar/security/jwt/middleware.py
@@ -251,5 +251,6 @@ async def authenticate_request(self, connection: ASGIConnection[Any, Any, Any, A
         auth_header = connection.headers.get(self.auth_header) or connection.cookies.get(self.auth_cookie_key)
         if not auth_header:
             raise NotAuthorizedException("No JWT token found in request header or cookies")
-        encoded_token = auth_header.partition(" ")[-1]
+        parts = auth_header.strip().split(maxsplit=1)
+        encoded_token = parts[-1] if parts else ""
         return await self.authenticate_token(encoded_token=encoded_token, connection=connection)