diff --git a/builder/vmware/iso/builder.go b/builder/vmware/iso/builder.go
index f1f7830f0..bac3dbdff 100755
--- a/builder/vmware/iso/builder.go
+++ b/builder/vmware/iso/builder.go
@@ -257,6 +257,7 @@ func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packe
 			Description:  "ISO",
 			ResultKey:    "iso_path",
 			Url:          b.config.ISOUrls,
+			Extension:    "iso",
 			TargetPath:   b.config.TargetPath,
 		},
 		&vmwcommon.StepOutputDir{