diff --git a/common/download.go b/common/download.go
index be53dfed4..4826d1dd1 100644
--- a/common/download.go
+++ b/common/download.go
@@ -86,8 +86,13 @@ func HashForType(t string) hash.Hash {
 func NewDownloadClient(c *DownloadConfig, bar *pb.ProgressBar) *DownloadClient {
 	const mtu = 1500 /* ethernet */ - 20 /* ipv4 */ - 20 /* tcp */
 
+	// If no custom progress-bar was specified, then create a default one.
+	if bar == nil {
+		bar = pb.New64(0)
+	}
+
+	// Create downloader map if it hasn't been specified already.
 	if c.DownloaderMap == nil {
-		// Create downloader map
 		c.DownloaderMap = map[string]Downloader{
 			"file":  &FileDownloader{progress: bar, bufferSize: nil},
 			"ftp":   &FTPDownloader{progress: bar, userInfo: url.UserPassword("anonymous", "anonymous@"), mtu: mtu},
diff --git a/common/download_test.go b/common/download_test.go
index a62fceb96..50bdfa971 100644
--- a/common/download_test.go
+++ b/common/download_test.go
@@ -36,7 +36,7 @@ func TestDownloadClientVerifyChecksum(t *testing.T) {
 		Checksum: checksum,
 	}
 
-	d := NewDownloadClient(config)
+	d := NewDownloadClient(config, nil)
 	result, err := d.VerifyChecksum(tf.Name())
 	if err != nil {
 		t.Fatalf("Verify err: %s", err)
@@ -59,7 +59,7 @@ func TestDownloadClient_basic(t *testing.T) {
 		Url:        ts.URL + "/basic.txt",
 		TargetPath: tf.Name(),
 		CopyFile:   true,
-	})
+	}, nil)
 
 	path, err := client.Get()
 	if err != nil {
@@ -95,7 +95,7 @@ func TestDownloadClient_checksumBad(t *testing.T) {
 		Hash:       HashForType("md5"),
 		Checksum:   checksum,
 		CopyFile:   true,
-	})
+	}, nil)
 	if _, err := client.Get(); err == nil {
 		t.Fatal("should error")
 	}
@@ -120,7 +120,7 @@ func TestDownloadClient_checksumGood(t *testing.T) {
 		Hash:       HashForType("md5"),
 		Checksum:   checksum,
 		CopyFile:   true,
-	})
+	}, nil)
 	path, err := client.Get()
 	if err != nil {
 		t.Fatalf("err: %s", err)
@@ -151,7 +151,7 @@ func TestDownloadClient_checksumNoDownload(t *testing.T) {
 		Hash:       HashForType("md5"),
 		Checksum:   checksum,
 		CopyFile:   true,
-	})
+	}, nil)
 	path, err := client.Get()
 	if err != nil {
 		t.Fatalf("err: %s", err)
@@ -190,7 +190,7 @@ func TestDownloadClient_resume(t *testing.T) {
 		Url:        ts.URL,
 		TargetPath: tf.Name(),
 		CopyFile:   true,
-	})
+	}, nil)
 	path, err := client.Get()
 	if err != nil {
 		t.Fatalf("err: %s", err)
@@ -250,7 +250,7 @@ func TestDownloadClient_usesDefaultUserAgent(t *testing.T) {
 		CopyFile:   true,
 	}
 
-	client := NewDownloadClient(config)
+	client := NewDownloadClient(config, nil)
 	_, err = client.Get()
 	if err != nil {
 		t.Fatal(err)
@@ -282,7 +282,7 @@ func TestDownloadClient_setsUserAgent(t *testing.T) {
 		CopyFile:   true,
 	}
 
-	client := NewDownloadClient(config)
+	client := NewDownloadClient(config, nil)
 	_, err = client.Get()
 	if err != nil {
 		t.Fatal(err)
@@ -381,7 +381,7 @@ func TestDownloadFileUrl(t *testing.T) {
 		CopyFile: false,
 	}
 
-	client := NewDownloadClient(config)
+	client := NewDownloadClient(config, nil)
 
 	// Verify that we fail to match the checksum
 	_, err = client.Get()
@@ -412,7 +412,7 @@ func SimulateFileUriDownload(t *testing.T, uri string) (string, error) {
 	}
 
 	// go go go
-	client := NewDownloadClient(config)
+	client := NewDownloadClient(config, nil)
 	path, err := client.Get()
 
 	// ignore any non-important checksum errors if it's not a unc path
diff --git a/common/step_download.go b/common/step_download.go
index 2ce48cfff..a4f249290 100644
--- a/common/step_download.go
+++ b/common/step_download.go
@@ -96,7 +96,7 @@ func (s *StepDownload) Run(state multistep.StateBag) multistep.StepAction {
 		}
 		downloadConfigs[i] = config
 
-		if match, _ := NewDownloadClient(config).VerifyChecksum(config.TargetPath); match {
+		if match, _ := NewDownloadClient(config, nil).VerifyChecksum(config.TargetPath); match {
 			ui.Message(fmt.Sprintf("Found already downloaded, initial checksum matched, no download needed: %s", url))
 			finalPath = config.TargetPath
 			break