diff --git a/post-processor/vsphere/post-processor.go b/post-processor/vsphere/post-processor.go
index 19f489928..c340662b1 100644
--- a/post-processor/vsphere/post-processor.go
+++ b/post-processor/vsphere/post-processor.go
@@ -1,10 +1,10 @@
 package vsphere
 
 import (
-	"bytes"
 	"fmt"
 	"log"
 	"net/url"
+	"os"
 	"os/exec"
 	"strings"
 
@@ -121,20 +121,49 @@ func (p *PostProcessor) PostProcess(ui packer.Ui, artifact packer.Artifact) (pac
 		ovftool_uri += "/Resources/" + p.config.ResourcePool
 	}
 
-	args := []string{
-		fmt.Sprintf("--noSSLVerify=%t", p.config.Insecure),
-		"--acceptAllEulas",
-		fmt.Sprintf("--name=\"%s\"", p.config.VMName),
-		fmt.Sprintf("--datastore=\"%s\"", p.config.Datastore),
-		fmt.Sprintf("--diskMode=\"%s\"", p.config.DiskMode),
-		fmt.Sprintf("--network=\"%s\"", p.config.VMNetwork),
-		fmt.Sprintf("--vmFolder=\"%s\"", p.config.VMFolder),
-		fmt.Sprintf("%s", source),
-		fmt.Sprintf("\"%s\"", ovftool_uri),
+	ui.Message(fmt.Sprintf("Uploading %s to vSphere", source))
+
+	args, err := p.BuildArgs(source, ovftool_uri)
+	if err != nil {
+		ui.Message(fmt.Sprintf("Failed: %s\n", err))
 	}
 
 	ui.Message(fmt.Sprintf("Uploading %s to vSphere", source))
 
+	log.Printf("Starting ovftool with parameters: %s", strings.Join(args, " "))
+	cmd := exec.Command("ovftool", args...)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	if err := cmd.Run(); err != nil {
+		return nil, false, fmt.Errorf("Failed: %s\n", err)
+	}
+
+	return artifact, false, nil
+}
+
+func (p *PostProcessor) BuildArgs(source, ovftool_uri string) ([]string, error) {
+	args := []string{
+		"--acceptAllEulas",
+		fmt.Sprintf(`--name=%s`, p.config.VMName),
+		fmt.Sprintf(`--datastore=%s`, p.config.Datastore),
+	}
+
+	if p.config.Insecure {
+		args = append(args, fmt.Sprintf(`--noSSLVerify=%t`, p.config.Insecure))
+	}
+
+	if p.config.DiskMode != "" {
+		args = append(args, fmt.Sprintf(`--diskMode=%s`, p.config.DiskMode))
+	}
+
+	if p.config.VMFolder != "" {
+		args = append(args, fmt.Sprintf(`--vmFolder=%s`, p.config.VMFolder))
+	}
+
+	if p.config.VMNetwork != "" {
+		args = append(args, fmt.Sprintf(`--network=%s`, p.config.VMNetwork))
+	}
+
 	if p.config.Overwrite == true {
 		args = append(args, "--overwrite")
 	}
@@ -143,16 +172,8 @@ func (p *PostProcessor) PostProcess(ui packer.Ui, artifact packer.Artifact) (pac
 		args = append(args, p.config.Options...)
 	}
 
-	ui.Message(fmt.Sprintf("Uploading %s to vSphere", source))
-	var out bytes.Buffer
-	log.Printf("Starting ovftool with parameters: %s", strings.Join(args, " "))
-	cmd := exec.Command("ovftool", args...)
-	cmd.Stdout = &out
-	if err := cmd.Run(); err != nil {
-		return nil, false, fmt.Errorf("Failed: %s\nStdout: %s", err, out.String())
-	}
+	args = append(args, fmt.Sprintf(`%s`, source))
+	args = append(args, fmt.Sprintf(`%s`, ovftool_uri))
 
-	ui.Message(fmt.Sprintf("%s", out.String()))
-
-	return artifact, false, nil
+	return args, nil
 }
diff --git a/post-processor/vsphere/post-processor_test.go b/post-processor/vsphere/post-processor_test.go
index 619049248..61b58789b 100644
--- a/post-processor/vsphere/post-processor_test.go
+++ b/post-processor/vsphere/post-processor_test.go
@@ -1 +1,42 @@
 package vsphere
+
+import (
+	"fmt"
+	"net/url"
+	"strings"
+	"testing"
+)
+
+func TestArgs(t *testing.T) {
+	var p PostProcessor
+
+	p.config.Username = "me"
+	p.config.Password = "notpassword"
+	p.config.Host = "myhost"
+	p.config.Datacenter = "mydc"
+	p.config.Cluster = "mycluster"
+	p.config.VMName = "my vm"
+	p.config.Datastore = "my datastore"
+	p.config.Insecure = true
+	p.config.DiskMode = "thin"
+	p.config.VMFolder = "my folder"
+
+	source := "something.vmx"
+	ovftool_uri := fmt.Sprintf("vi://%s:%s@%s/%s/host/%s",
+		url.QueryEscape(p.config.Username),
+		url.QueryEscape(p.config.Password),
+		p.config.Host,
+		p.config.Datacenter,
+		p.config.Cluster)
+
+	if p.config.ResourcePool != "" {
+		ovftool_uri += "/Resources/" + p.config.ResourcePool
+	}
+
+	args, err := p.BuildArgs(source, ovftool_uri)
+	if err != nil {
+		t.Errorf("Error: %s", err)
+	}
+
+	t.Logf("ovftool %s", strings.Join(args, " "))
+}