diff --git a/src/Enum/LoginField.php b/src/Enum/LoginField.php
index 79ae8ef..d421d8b 100644
--- a/src/Enum/LoginField.php
+++ b/src/Enum/LoginField.php
@@ -6,4 +6,5 @@ enum LoginField
 {
     case Email;
     case Username;
+    case EmailOrUsername;
 }
diff --git a/src/Service/UsersService.php b/src/Service/UsersService.php
index 393764a..c706e5e 100644
--- a/src/Service/UsersService.php
+++ b/src/Service/UsersService.php
@@ -105,9 +105,11 @@ public function getLoginField(): LoginField
 
     public function getLoginValue(UserModel $user): ?string
     {
-        return $this->loginField === LoginField::Email
-            ? $user->getEmail()
-            : $user->getUsername();
+        return match($this->loginField) {
+            LoginField::Email => $user->getEmail(),
+            LoginField::Username => $user->getUsername(),
+            LoginField::EmailOrUsername => $user->getUsername() ?? $user->getEmail(),
+        };
     }
 
     /**
@@ -258,9 +260,11 @@ public function getByUsername(string $username): ?UserModel
     #[\Override]
     public function getByLogin(string $login): ?UserModel
     {
-        return $this->loginField === LoginField::Email
-            ? $this->getByEmail($login)
-            : $this->getByUsername($login);
+        return match($this->loginField) {
+            LoginField::Email => $this->getByEmail($login),
+            LoginField::Username => $this->getByUsername($login),
+            LoginField::EmailOrUsername => $this->getByUsername($login) ?? $this->getByEmail($login),
+        };
     }
 
     /**
diff --git a/tests/TestUsersBase.php b/tests/TestUsersBase.php
index bf26f80..9d47b70 100644
--- a/tests/TestUsersBase.php
+++ b/tests/TestUsersBase.php
@@ -31,7 +31,7 @@ public function __chooseValue($forUsername, $forEmail): string
     {
         return match ($this->loginField) {
             LoginField::Email => $forEmail,
-            LoginField::Username => $forUsername,
+            LoginField::Username, LoginField::EmailOrUsername => $forUsername,
         };
     }
 
diff --git a/tests/UsersDBDatasetByEmailOrUsernameTest.php b/tests/UsersDBDatasetByEmailOrUsernameTest.php
new file mode 100644
index 0000000..ba74617
--- /dev/null
+++ b/tests/UsersDBDatasetByEmailOrUsernameTest.php
@@ -0,0 +1,59 @@
+<?php
+
+namespace Tests;
+
+use ByJG\Authenticate\Enum\LoginField;
+
+class UsersDBDatasetByEmailOrUsernameTest extends UsersDBDatasetByUsernameTestUsersBase
+{
+    #[\Override]
+    public function setUp(): void
+    {
+        $this->__setUp(LoginField::EmailOrUsername);
+    }
+
+    #[\Override]
+    public function testIsValidUser(): void
+    {
+        // Both username and email must work
+        $user = $this->object->isValidUser('user3', 'pwd3');
+        $this->assertEquals('User 3', $user->getName());
+
+        $user = $this->object->isValidUser('user3@gmail.com', 'pwd3');
+        $this->assertEquals('User 3', $user->getName());
+
+        // Wrong password returns null regardless of field used
+        $this->assertNull($this->object->isValidUser('user3', 'wrongpwd'));
+        $this->assertNull($this->object->isValidUser('user3@gmail.com', 'wrongpwd'));
+
+        // Non-existent identifier returns null
+        $this->assertNull($this->object->isValidUser('nonexistent', 'pwd3'));
+    }
+
+    public function testGetByLoginWithUsername(): void
+    {
+        $user = $this->object->getByLogin('user1');
+        $this->assertNotNull($user);
+        $this->assertEquals('User 1', $user->getName());
+        $this->assertEquals('user1', $user->getUsername());
+    }
+
+    public function testGetByLoginWithEmail(): void
+    {
+        $user = $this->object->getByLogin('user1@gmail.com');
+        $this->assertNotNull($user);
+        $this->assertEquals('User 1', $user->getName());
+        $this->assertEquals('user1@gmail.com', $user->getEmail());
+    }
+
+    public function testGetLoginValueReturnsUsername(): void
+    {
+        $user = $this->object->getByLogin('user2');
+        $this->assertEquals('user2', $this->object->getLoginValue($user));
+    }
+
+    public function testGetLoginFieldIsEmailOrUsername(): void
+    {
+        $this->assertEquals(LoginField::EmailOrUsername, $this->object->getLoginField());
+    }
+}
\ No newline at end of file