diff --git a/core/user.php b/core/user.php
index bf4f42fe..4f79e908 100644
--- a/core/user.php
+++ b/core/user.php
@@ -116,9 +116,12 @@ class User
     public static function by_name_and_pass(string $name, string $pass): ?User
     {
         $my_user = User::by_name($name);
-        if (!$my_user && strpos($name, "_") !== false) {
+
+        // If user tried to log in as "foo bar" and failed, try "foo_bar"
+        if (!$my_user && strpos($name, " ") !== false) {
             $my_user = User::by_name(str_replace(" ", "_", $name));
         }
+        
         if ($my_user) {
             if ($my_user->passhash == md5(strtolower($name) . $pass)) {
                 log_info("core-user", "Migrating from md5 to bcrypt for $name");