diff --git a/builder/googlecompute/config.go b/builder/googlecompute/config.go
index eebea011f..317d64ace 100644
--- a/builder/googlecompute/config.go
+++ b/builder/googlecompute/config.go
@@ -59,6 +59,8 @@ func NewConfig(raws ...interface{}) (*Config, []string, error) {
 		return nil, nil, err
 	}
 
+	var errs *packer.MultiError
+
 	// Set defaults.
 	if c.Network == "" {
 		c.Network = "default"
@@ -73,7 +75,12 @@ func NewConfig(raws ...interface{}) (*Config, []string, error) {
 	}
 
 	if c.ImageName == "" {
-		c.ImageName = "packer-{{timestamp}}"
+		img, err := interpolate.Render("packer-{{timestamp}}", nil)
+		if err != nil {
+			errs = packer.MultiErrorAppend(errs,
+				fmt.Errorf("Unable to parse image name: %s ", err))
+			c.ImageName = img
+		}
 	}
 
 	if c.InstanceName == "" {
@@ -96,7 +103,6 @@ func NewConfig(raws ...interface{}) (*Config, []string, error) {
 		c.Comm.SSHUsername = "root"
 	}
 
-	var errs *packer.MultiError
 	if es := c.Comm.Prepare(&c.ctx); len(es) > 0 {
 		errs = packer.MultiErrorAppend(errs, es...)
 	}
diff --git a/builder/googlecompute/config_test.go b/builder/googlecompute/config_test.go
index 93997912e..581c1425b 100644
--- a/builder/googlecompute/config_test.go
+++ b/builder/googlecompute/config_test.go
@@ -2,48 +2,10 @@ package googlecompute
 
 import (
 	"io/ioutil"
+	"strings"
 	"testing"
 )
 
-func testConfig(t *testing.T) map[string]interface{} {
-	return map[string]interface{}{
-		"account_file": testAccountFile(t),
-		"project_id":   "hashicorp",
-		"source_image": "foo",
-		"zone":         "us-east-1a",
-	}
-}
-
-func testConfigStruct(t *testing.T) *Config {
-	c, warns, errs := NewConfig(testConfig(t))
-	if len(warns) > 0 {
-		t.Fatalf("bad: %#v", len(warns))
-	}
-	if errs != nil {
-		t.Fatalf("bad: %#v", errs)
-	}
-
-	return c
-}
-
-func testConfigErr(t *testing.T, warns []string, err error, extra string) {
-	if len(warns) > 0 {
-		t.Fatalf("bad: %#v", warns)
-	}
-	if err == nil {
-		t.Fatalf("should error: %s", extra)
-	}
-}
-
-func testConfigOk(t *testing.T, warns []string, err error) {
-	if len(warns) > 0 {
-		t.Fatalf("bad: %#v", warns)
-	}
-	if err != nil {
-		t.Fatalf("bad: %s", err)
-	}
-}
-
 func TestConfigPrepare(t *testing.T) {
 	cases := []struct {
 		Key   string
@@ -181,6 +143,54 @@ func TestConfigDefaults(t *testing.T) {
 	}
 }
 
+func TestImageName(t *testing.T) {
+	c, _, _ := NewConfig(testConfig(t))
+	if strings.Contains(c.ImageName, "{{timestamp}}") {
+		t.Errorf("ImageName should be interpolated; found %s", c.ImageName)
+	}
+}
+
+// Helper stuff below
+
+func testConfig(t *testing.T) map[string]interface{} {
+	return map[string]interface{}{
+		"account_file": testAccountFile(t),
+		"project_id":   "hashicorp",
+		"source_image": "foo",
+		"zone":         "us-east-1a",
+	}
+}
+
+func testConfigStruct(t *testing.T) *Config {
+	c, warns, errs := NewConfig(testConfig(t))
+	if len(warns) > 0 {
+		t.Fatalf("bad: %#v", len(warns))
+	}
+	if errs != nil {
+		t.Fatalf("bad: %#v", errs)
+	}
+
+	return c
+}
+
+func testConfigErr(t *testing.T, warns []string, err error, extra string) {
+	if len(warns) > 0 {
+		t.Fatalf("bad: %#v", warns)
+	}
+	if err == nil {
+		t.Fatalf("should error: %s", extra)
+	}
+}
+
+func testConfigOk(t *testing.T, warns []string, err error) {
+	if len(warns) > 0 {
+		t.Fatalf("bad: %#v", warns)
+	}
+	if err != nil {
+		t.Fatalf("bad: %s", err)
+	}
+}
+
 func testAccountFile(t *testing.T) string {
 	tf, err := ioutil.TempFile("", "packer")
 	if err != nil {