diff --git a/public/profile.php b/public/profile.php
index a35260e..29ffb91 100644
--- a/public/profile.php
+++ b/public/profile.php
@@ -15,7 +15,7 @@ use Misuzu\Users\Assets\UserImageAssetFileTooLargeException;
 
 require_once '../misuzu.php';
 
-$userId = !empty($_GET['u']) && is_string($_GET['u']) ? $_GET['u'] : 0;
+$userId = !empty($_GET['u']) && is_string($_GET['u']) ? trim($_GET['u']) : 0;
 $profileMode = !empty($_GET['m']) && is_string($_GET['m']) ? (string)$_GET['m'] : '';
 $isEditing = !empty($_GET['edit']) && is_string($_GET['edit']) ? (bool)$_GET['edit'] : !empty($_POST) && is_array($_POST);
 
diff --git a/src/Users/User.php b/src/Users/User.php
index 89625f0..14d7f6b 100644
--- a/src/Users/User.php
+++ b/src/Users/User.php
@@ -806,6 +806,9 @@ class User implements HasRankInterface, JsonSerializable {
         });
     }
     public static function byUsername(string $username): ?self {
+        if(empty($username))
+            throw new UserNotFoundException;
+
         $username = mb_strtolower($username);
 
         if(str_starts_with($username, 'flappyzor'))
@@ -823,7 +826,11 @@ class User implements HasRankInterface, JsonSerializable {
         });
     }
     public static function byEMailAddress(string $address): ?self {
+        if(empty($address))
+            throw new UserNotFoundException;
+
         $address = mb_strtolower($address);
+
         return self::memoizer()->find(function($user) use ($address) {
             return mb_strtolower($user->getEmailAddress()) === $address;
         }, function() use ($address) {
@@ -836,6 +843,9 @@ class User implements HasRankInterface, JsonSerializable {
         });
     }
     public static function byUsernameOrEMailAddress(string $usernameOrAddress): self {
+        if(empty($usernameOrAddress))
+            throw new UserNotFoundException;
+
         $usernameOrAddressLower = mb_strtolower($usernameOrAddress);
 
         if(!str_contains($usernameOrAddressLower, '@') && str_starts_with($usernameOrAddressLower, 'flappyzor'))
@@ -859,6 +869,9 @@ class User implements HasRankInterface, JsonSerializable {
             ->fetchObject(self::class);
     }
     public static function findForProfile($userIdOrName): ?self {
+        if(empty($userIdOrName))
+            throw new UserNotFoundException;
+
         $userIdOrNameLower = mb_strtolower($userIdOrName);
 
         if(str_starts_with($userIdOrNameLower, 'flappyzor'))