diff --git a/src/Transport/CustomTransport.php b/src/Transport/CustomTransport.php
index 7d74b5f..5f897b5 100644
--- a/src/Transport/CustomTransport.php
+++ b/src/Transport/CustomTransport.php
@@ -35,13 +35,14 @@ public function configure(SiteProcess $process)
      */
     public function wrap($args)
     {
-        $transport = Shell::preEscaped($this->siteAlias->get('custom.command', ''));
+        $cmd = $this->siteAlias->get('custom.command', '');
+        $transport = $cmd ? [Shell::preEscaped($cmd)] : [];
         $commandToExecute = $this->getCommandToExecute($args);
 
-        return array_merge(
+        return array_filter(array_merge(
             $transport,
             $commandToExecute
-        );
+        ));
     }
 
     /**
diff --git a/tests/Transport/CustomTransportTest.php b/tests/Transport/CustomTransportTest.php
index 72351fb..1dc477a 100644
--- a/tests/Transport/CustomTransportTest.php
+++ b/tests/Transport/CustomTransportTest.php
@@ -47,8 +47,8 @@ public function wrapTestValues()
     public function testWrap($expected, $siteAliasData)
     {
         $siteAlias = new SiteAlias($siteAliasData, '@alias.dev');
-        $dockerTransport = new CustomTransport($siteAlias);
-        $actual = $dockerTransport->wrap(['ls']);
+        $customTransport = new CustomTransport($siteAlias);
+        $actual = $customTransport->wrap(['ls']);
         $this->assertEquals($expected, implode(' ', $actual));
     }
 }