diff --git a/test/PHPMailer/SetFromTest.php b/test/PHPMailer/SetFromTest.php
index 1952747b..6e65402c 100644
--- a/test/PHPMailer/SetFromTest.php
+++ b/test/PHPMailer/SetFromTest.php
@@ -108,6 +108,20 @@ final class SetFromTest extends TestCase
         self::assertSame('', $this->Mail->Sender, 'Sender has been overruled');
     }
 
+    /**
+     * Test setting the From address, but not overruling an existing, non-empty Sender value.
+     */
+    public function testSetFromDoesNotOverruleExistingSender()
+    {
+        $sender             = 'donotoverrule@example.com';
+        $this->Mail->Sender = $sender;
+
+        $result = $this->Mail->setFrom('overruled@example.com');
+
+        self::assertTrue($result, 'setFrom failed');
+        self::assertSame($sender, $this->Mail->Sender, 'Sender has been overruled');
+    }
+
     /**
      * Test unsuccesfully setting the From, FromName and Sender properties.
      */