diff --git a/src/Transport/Sendmail.php b/src/Transport/Sendmail.php
index 98ee2142..1929e82d 100644
--- a/src/Transport/Sendmail.php
+++ b/src/Transport/Sendmail.php
@@ -255,6 +255,9 @@ protected function prepareParameters(Mail\Message $message)
         }
 
         $parameters = (string) $this->parameters;
+        if (preg_match('/^\-f.+$/', $parameters) || strpos($parameters, ' -f') !== false) {
+            return $parameters;
+        }
 
         $sender = $message->getSender();
         if ($sender instanceof AddressInterface) {
diff --git a/test/Transport/SendmailTest.php b/test/Transport/SendmailTest.php
index 111f8f3b..525a0435 100644
--- a/test/Transport/SendmailTest.php
+++ b/test/Transport/SendmailTest.php
@@ -282,4 +282,30 @@ public function testHeadersToAndSubjectAreNotDuplicated()
         $this->assertNotRegExp('/^To: matthew\@example\.org$/m', $this->additional_headers);
         $this->assertNotRegExp('/^Subject: Greetings and Salutations!$/m', $this->additional_headers);
     }
+
+    public function testNotSetOptionAutomaticallyOnLeadingF()
+    {
+        if ($this->operating_system == 'WIN') {
+            $this->markTestSkipped('This test is *nix-specific');
+        }
+
+        $message = $this->getMessage();
+        $this->transport->setParameters('-f\'foo@example.com\'');
+
+        $this->transport->send($message);
+        $this->assertEquals('-f\'foo@example.com\'', $this->additional_parameters);
+    }
+
+    public function testNotSetOptionAutomaticallyOnMiddleF()
+    {
+        if ($this->operating_system == 'WIN') {
+            $this->markTestSkipped('This test is *nix-specific');
+        }
+
+        $message = $this->getMessage();
+        $this->transport->setParameters('-bs -f\'foo@example.com\'');
+
+        $this->transport->send($message);
+        $this->assertEquals('-bs -f\'foo@example.com\'', $this->additional_parameters);
+    }
 }