diff --git a/web/app/controllers/super_manage.php b/web/app/controllers/super_manage.php
index 6aa3191..4e688d7 100644
--- a/web/app/controllers/super_manage.php
+++ b/web/app/controllers/super_manage.php
@@ -142,11 +142,23 @@
 				break;
 			case 'problem_uploader':
 				DB::update("update user_info set usergroup = 'U' where username = '{$username}'");
-				DB::update("update user_info set usertype = 'problem_uploader' where username = '{$username}'");
+				$user = queryUser($username);
+				$usertype = explode(',', $user['usertype']);
+				if (!in_array('problem_uploader', $usertype)) {
+					$usertype[] = 'problem_uploader';
+				}
+				$usertype = implode(',', $usertype);
+				DB::update("update user_info set usertype = '{$usertype}' where username = '{$username}'");
 				break;
 			case 'problem_manager':
 				DB::update("update user_info set usergroup = 'U' where username = '{$username}'");
-				DB::update("update user_info set usertype = 'problem_manager' where username = '{$username}'");
+				$user = queryUser($username);
+				$usertype = explode(',', $user['usertype']);
+				if (!in_array('problem_manager', $usertype)) {
+					$usertype[] = 'problem_manager';
+				}
+				$usertype = implode(',', $usertype);
+				DB::update("update user_info set usertype = '{$usertype}' where username = '{$username}'");
 				break;
 			case 'superuser':
 				DB::update("update user_info set usergroup = 'S' where username = '{$username}'");
@@ -427,7 +439,7 @@ EOD;
 		echo <<<EOD
 			<tr>
 				<td>${hislink}</td>
-				<td>{$row['usergroup']}</td>
+				<td>{$row['usergroup']}, {$row['usertype']}</td>
 				<td>{$row['register_time']}</td>
 			</tr>
 EOD;
diff --git a/web/app/libs/uoj-utility-lib.php b/web/app/libs/uoj-utility-lib.php
index 6fecced..902d7ef 100644
--- a/web/app/libs/uoj-utility-lib.php
+++ b/web/app/libs/uoj-utility-lib.php
@@ -130,10 +130,18 @@ function blog_name_decode($name) {
 }
 
 function isProblemUploader($user) {
-	return $user != null && $user['usertype'] == 'problem_uploader';
+	if ($user == null) {
+		return false;
+	}
+	$usertype = explode(',', $user['usertype']);
+	return in_array('problem_uploader', $usertype);
 }
 function isProblemManager($user) {
-	return $user != null && $user['usertype'] == 'problem_manager';
+	if ($user == null) {
+		return false;
+	}
+	$usertype = explode(',', $user['usertype']);
+	return in_array('problem_manager', $usertype);
 }
 
 function isSuperUser($user) {