diff --git a/src/main/java/com/example/FakeAuthServlet.java b/src/main/java/com/example/FakeAuthServlet.java
index f28b1dd..6979689 100644
--- a/src/main/java/com/example/FakeAuthServlet.java
+++ b/src/main/java/com/example/FakeAuthServlet.java
@@ -18,6 +18,7 @@
 
 import java.io.IOException;
 import java.net.URLDecoder;
+import java.net.URLEncoder;
 
 import javax.servlet.annotation.WebServlet;
 import javax.servlet.http.HttpServlet;
@@ -36,7 +37,7 @@ protected void doGet(HttpServletRequest req, HttpServletResponse res) throws IOE
             URLDecoder.decode(req.getParameter("redirect_uri"), "UTF8"),
             "xxxxxx",
             req.getParameter("state"));
-    String loginUrl = res.encodeRedirectURL("/login?responseurl=" + redirectURL);
+    String loginUrl = res.encodeRedirectURL("/login?responseurl=" + URLEncoder.encode(redirectURL, "UTF8"));
     res.setStatus(HttpServletResponse.SC_MOVED_TEMPORARILY);
     res.setHeader("Location", loginUrl);
     res.getWriter().flush();