diff --git a/src/Entity/UserSystem/User.php b/src/Entity/UserSystem/User.php
index f39f5078..ac5d9558 100644
--- a/src/Entity/UserSystem/User.php
+++ b/src/Entity/UserSystem/User.php
@@ -506,11 +506,18 @@ class User extends AttachmentContainingDBElement implements UserInterface, HasPe
      */
     public function getFullName(bool $including_username = false): string
     {
+        $tmp = $this->getFirstName();
+        //Dont add a space, if the name has only one part (it would look strange)
+        if (!empty($this->getFirstName()) && !empty($this->getLastName())) {
+            $tmp .= ' ';
+        }
+        $tmp .= $this->getLastName();
+
         if ($including_username) {
-            return sprintf('%s %s (@%s)', $this->getFirstName(), $this->getLastName(), $this->getName());
+            $tmp .= sprintf(' (@%s)', $this->getName());
         }
 
-        return sprintf('%s %s', $this->getFirstName(), $this->getLastName());
+        return $tmp;
     }
 
     /**
diff --git a/tests/Entity/UserSystem/UserTest.php b/tests/Entity/UserSystem/UserTest.php
index 813d5435..4ac24c80 100644
--- a/tests/Entity/UserSystem/UserTest.php
+++ b/tests/Entity/UserSystem/UserTest.php
@@ -58,6 +58,9 @@ class UserTest extends TestCase
 
         $this->assertSame('John Doe', $user->getFullName(false));
         $this->assertSame('John Doe (@username)', $user->getFullName(true));
+
+        $user->setLastName('');
+        $this->assertSame('John (@username)', $user->getFullName(true));
     }
 
     public function googleAuthenticatorEnabledDataProvider(): array