diff --git a/app/Access/LoginService.php b/app/Access/LoginService.php
index cc48e0f9b..6607969af 100644
--- a/app/Access/LoginService.php
+++ b/app/Access/LoginService.php
@@ -5,6 +5,7 @@ namespace BookStack\Access;
 use BookStack\Access\Mfa\MfaSession;
 use BookStack\Activity\ActivityType;
 use BookStack\Exceptions\LoginAttemptException;
+use BookStack\Exceptions\LoginAttemptInvalidUserException;
 use BookStack\Exceptions\StoppedAuthenticationException;
 use BookStack\Facades\Activity;
 use BookStack\Facades\Theme;
@@ -29,10 +30,14 @@ class LoginService
      * a reason to (MFA or Unconfirmed Email).
      * Returns a boolean to indicate the current login result.
      *
-     * @throws StoppedAuthenticationException
+     * @throws StoppedAuthenticationException|LoginAttemptInvalidUserException
      */
     public function login(User $user, string $method, bool $remember = false): void
     {
+        if ($user->isGuest()) {
+            throw new LoginAttemptInvalidUserException('Login not allowed for guest user');
+        }
+
         if ($this->awaitingEmailConfirmation($user) || $this->needsMfaVerification($user)) {
             $this->setLastLoginAttemptedForUser($user, $method, $remember);
 
@@ -58,7 +63,7 @@ class LoginService
      *
      * @throws Exception
      */
-    public function reattemptLoginFor(User $user)
+    public function reattemptLoginFor(User $user): void
     {
         if ($user->id !== ($this->getLastLoginAttemptUser()->id ?? null)) {
             throw new Exception('Login reattempt user does align with current session state');
@@ -152,16 +157,40 @@ class LoginService
      */
     public function attempt(array $credentials, string $method, bool $remember = false): bool
     {
+        if ($this->areCredentialsForGuest($credentials)) {
+            return false;
+        }
+
         $result = auth()->attempt($credentials, $remember);
         if ($result) {
             $user = auth()->user();
             auth()->logout();
-            $this->login($user, $method, $remember);
+            try {
+                $this->login($user, $method, $remember);
+            } catch (LoginAttemptInvalidUserException $e) {
+                // Catch and return false for non-login accounts
+                // so it looks like a normal invalid login.
+                return false;
+            }
         }
 
         return $result;
     }
 
+    /**
+     * Check if the given credentials are likely for the system guest account.
+     */
+    protected function areCredentialsForGuest(array $credentials): bool
+    {
+        if (isset($credentials['email'])) {
+            return User::query()->where('email', '=', $credentials['email'])
+                ->where('system_name', '=', 'public')
+                ->exists();
+        }
+
+        return false;
+    }
+
     /**
      * Logs the current user out of the application.
      * Returns an app post-redirect path.
diff --git a/app/Exceptions/LoginAttemptInvalidUserException.php b/app/Exceptions/LoginAttemptInvalidUserException.php
new file mode 100644
index 000000000..163484c5a
--- /dev/null
+++ b/app/Exceptions/LoginAttemptInvalidUserException.php
@@ -0,0 +1,7 @@
+<?php
+
+namespace BookStack\Exceptions;
+
+class LoginAttemptInvalidUserException extends LoginAttemptException
+{
+}
diff --git a/tests/Auth/AuthTest.php b/tests/Auth/AuthTest.php
index 0164978d8..bffd8bbdb 100644
--- a/tests/Auth/AuthTest.php
+++ b/tests/Auth/AuthTest.php
@@ -3,6 +3,7 @@
 namespace Tests\Auth;
 
 use BookStack\Access\Mfa\MfaSession;
+use Illuminate\Support\Facades\Hash;
 use Illuminate\Testing\TestResponse;
 use Tests\TestCase;
 
@@ -144,6 +145,25 @@ class AuthTest extends TestCase
         $resp->assertSee('Too many login attempts. Please try again in');
     }
 
+    public function test_login_specifically_disabled_for_guest_account()
+    {
+        $guest = $this->users->guest();
+
+        $resp = $this->post('/login', ['email' => $guest->email, 'password' => 'password']);
+        $resp->assertRedirect('/login');
+        $resp = $this->followRedirects($resp);
+        $resp->assertSee('These credentials do not match our records.');
+
+        // Test login even with password somehow set
+        $guest->password = Hash::make('password');
+        $guest->save();
+
+        $resp = $this->post('/login', ['email' => $guest->email, 'password' => 'password']);
+        $resp->assertRedirect('/login');
+        $resp = $this->followRedirects($resp);
+        $resp->assertSee('These credentials do not match our records.');
+    }
+
     /**
      * Perform a login.
      */