diff --git a/builder/virtualbox/builder.go b/builder/virtualbox/builder.go
index e82af8d20..8b6fc0ab3 100644
--- a/builder/virtualbox/builder.go
+++ b/builder/virtualbox/builder.go
@@ -181,6 +181,10 @@ func (b *Builder) Prepare(raws ...interface{}) error {
 		b.config.RawShutdownTimeout = "5m"
 	}
 
+	if b.config.RawSSHWaitTimeout == "" {
+		b.config.RawSSHWaitTimeout = "20m"
+	}
+
 	b.config.ShutdownTimeout, err = time.ParseDuration(b.config.RawShutdownTimeout)
 	if err != nil {
 		errs = append(errs, fmt.Errorf("Failed parsing shutdown_timeout: %s", err))
@@ -194,10 +198,6 @@ func (b *Builder) Prepare(raws ...interface{}) error {
 		errs = append(errs, errors.New("An ssh_username must be specified."))
 	}
 
-	if b.config.RawSSHWaitTimeout == "" {
-		b.config.RawSSHWaitTimeout = "20m"
-	}
-
 	b.config.SSHWaitTimeout, err = time.ParseDuration(b.config.RawSSHWaitTimeout)
 	if err != nil {
 		errs = append(errs, fmt.Errorf("Failed parsing ssh_wait_timeout: %s", err))
diff --git a/builder/virtualbox/builder_test.go b/builder/virtualbox/builder_test.go
index de880beb7..f8902a44d 100644
--- a/builder/virtualbox/builder_test.go
+++ b/builder/virtualbox/builder_test.go
@@ -68,6 +68,10 @@ func TestBuilderPrepare_BootWait(t *testing.T) {
 		t.Fatalf("err: %s", err)
 	}
 
+	if b.config.RawBootWait != "10s" {
+		t.Fatalf("bad value: %s", b.config.RawBootWait)
+	}
+
 	// Test with a bad boot_wait
 	config["boot_wait"] = "this is not good"
 	err = b.Prepare(config)
@@ -324,9 +328,20 @@ func TestBuilderPrepare_SSHWaitTimeout(t *testing.T) {
 	var b Builder
 	config := testConfig()
 
+	// Test a default boot_wait
+	delete(config, "ssh_wait_timeout")
+	err := b.Prepare(config)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	if b.config.RawSSHWaitTimeout != "20m" {
+		t.Fatalf("bad value: %s", b.config.RawSSHWaitTimeout)
+	}
+
 	// Test with a bad value
 	config["ssh_wait_timeout"] = "this is not good"
-	err := b.Prepare(config)
+	err = b.Prepare(config)
 	if err == nil {
 		t.Fatal("should have error")
 	}