diff --git a/builder/virtualbox/common/driver_4_2.go b/builder/virtualbox/common/driver_4_2.go
index 9bfa3baf1..1a2c8541d 100644
--- a/builder/virtualbox/common/driver_4_2.go
+++ b/builder/virtualbox/common/driver_4_2.go
@@ -28,7 +28,7 @@ func (d *VBox42Driver) CreateSATAController(vmName string, name string, portcoun
 	if strings.HasPrefix(version, "0.") || strings.HasPrefix(version, "1.") || strings.HasPrefix(version, "2.") ||
 		strings.HasPrefix(version, "3.") || strings.HasPrefix(version, "4.0") || strings.HasPrefix(version, "4.1") ||
 		strings.HasPrefix(version, "4.2") {
-		portCountArg := "--sataportcount"
+		portCountArg = "--sataportcount"
 	}
 
 	command := []string{