diff --git a/builtin/providers/google/config.go b/builtin/providers/google/config.go
index 91f8992a07..54c115b4b5 100644
--- a/builtin/providers/google/config.go
+++ b/builtin/providers/google/config.go
@@ -29,20 +29,6 @@ func (c *Config) loadAndValidate() error {
 	var account accountFile
 	var secrets clientSecretsFile
 
-	// TODO: validation that it isn't blank
-	if c.AccountFile == "" {
-		c.AccountFile = os.Getenv("GOOGLE_ACCOUNT_FILE")
-	}
-	if c.ClientSecretsFile == "" {
-		c.ClientSecretsFile = os.Getenv("GOOGLE_CLIENT_FILE")
-	}
-	if c.Project == "" {
-		c.Project = os.Getenv("GOOGLE_PROJECT")
-	}
-	if c.Region == "" {
-		c.Region = os.Getenv("GOOGLE_REGION")
-	}
-
 	if err := loadJSON(&account, c.AccountFile); err != nil {
 		return fmt.Errorf(
 			"Error loading account file '%s': %s",
diff --git a/builtin/providers/google/provider.go b/builtin/providers/google/provider.go
index 593b8559b5..ea630bbfef 100644
--- a/builtin/providers/google/provider.go
+++ b/builtin/providers/google/provider.go
@@ -1,6 +1,8 @@
 package google
 
 import (
+	"os"
+
 	"github.com/hashicorp/terraform/helper/schema"
 	"github.com/hashicorp/terraform/terraform"
 )
@@ -10,23 +12,27 @@ func Provider() terraform.ResourceProvider {
 	return &schema.Provider{
 		Schema: map[string]*schema.Schema{
 			"account_file": &schema.Schema{
-				Type:     schema.TypeString,
-				Required: true,
+				Type:        schema.TypeString,
+				Required:    true,
+				DefaultFunc: envDefaultFunc("GOOGLE_ACCOUNT_FILE"),
 			},
 
 			"client_secrets_file": &schema.Schema{
-				Type:     schema.TypeString,
-				Required: true,
+				Type:        schema.TypeString,
+				Required:    true,
+				DefaultFunc: envDefaultFunc("GOOGLE_CLIENT_FILE"),
 			},
 
 			"project": &schema.Schema{
-				Type:     schema.TypeString,
-				Required: true,
+				Type:        schema.TypeString,
+				Required:    true,
+				DefaultFunc: envDefaultFunc("GOOGLE_PROJECT"),
 			},
 
 			"region": &schema.Schema{
-				Type:     schema.TypeString,
-				Required: true,
+				Type:        schema.TypeString,
+				Required:    true,
+				DefaultFunc: envDefaultFunc("GOOGLE_REGION"),
 			},
 		},
 
@@ -43,6 +49,16 @@ func Provider() terraform.ResourceProvider {
 	}
 }
 
+func envDefaultFunc(k string) schema.SchemaDefaultFunc {
+	return func() (interface{}, error) {
+		if v := os.Getenv(k); v != "" {
+			return v, nil
+		}
+
+		return nil, nil
+	}
+}
+
 func providerConfigure(d *schema.ResourceData) (interface{}, error) {
 	config := Config{
 		AccountFile:       d.Get("account_file").(string),
diff --git a/builtin/providers/google/provider_test.go b/builtin/providers/google/provider_test.go
index f4903bd272..d5a32be33e 100644
--- a/builtin/providers/google/provider_test.go
+++ b/builtin/providers/google/provider_test.go
@@ -40,4 +40,8 @@ func testAccPreCheck(t *testing.T) {
 	if v := os.Getenv("GOOGLE_PROJECT"); v == "" {
 		t.Fatal("GOOGLE_PROJECT must be set for acceptance tests")
 	}
+
+	if v := os.Getenv("GOOGLE_REGION"); v != "us-central1" {
+		t.Fatal("GOOGLE_REGION must be set to us-central1 for acceptance tests")
+	}
 }
diff --git a/builtin/providers/google/resource_compute_instance.go b/builtin/providers/google/resource_compute_instance.go
index f6b0fde7a1..92065fb687 100644
--- a/builtin/providers/google/resource_compute_instance.go
+++ b/builtin/providers/google/resource_compute_instance.go
@@ -514,10 +514,10 @@ func resourceInstanceTags(d *schema.ResourceData) *compute.Tags {
 	// Calculate the tags
 	var tags *compute.Tags
 	if v := d.Get("tags"); v != nil {
-		vs := v.(*schema.Set).List()
+		vs := v.(*schema.Set)
 		tags = new(compute.Tags)
-		tags.Items = make([]string, len(vs))
-		for i, v := range v.(*schema.Set).List() {
+		tags.Items = make([]string, vs.Len())
+		for i, v := range vs.List() {
 			tags.Items[i] = v.(string)
 		}
 
diff --git a/builtin/providers/google/resource_compute_instance_test.go b/builtin/providers/google/resource_compute_instance_test.go
index 78c01e04e0..f765a44c44 100644
--- a/builtin/providers/google/resource_compute_instance_test.go
+++ b/builtin/providers/google/resource_compute_instance_test.go
@@ -52,9 +52,6 @@ func TestAccComputeInstance_IP(t *testing.T) {
 	})
 }
 
-//!NB requires that disk with name terraform-test-disk is present in gce,
-//if created as dependency then it tries to remove it while it is still attached
-//to instance and that fails with an error
 func TestAccComputeInstance_disks(t *testing.T) {
 	var instance compute.Instance
 
@@ -66,6 +63,8 @@ func TestAccComputeInstance_disks(t *testing.T) {
 			resource.TestStep{
 				Config: testAccComputeInstance_disks,
 				Check: resource.ComposeTestCheckFunc(
+					testAccCheckComputeInstanceExists(
+						"google_compute_instance.foobar", &instance),
 					testAccCheckComputeInstanceDisk(&instance, "terraform-test", true, true),
 					testAccCheckComputeInstanceDisk(&instance, "terraform-test-disk", false, false),
 				),
@@ -287,6 +286,13 @@ resource "google_compute_instance" "foobar" {
 }`
 
 const testAccComputeInstance_disks = `
+resource "google_compute_disk" "foobar" {
+	name = "terraform-test-disk"
+	size = 10
+	type = "pd-ssd"
+	zone = "us-central1-a"
+}
+
 resource "google_compute_instance" "foobar" {
 	name = "terraform-test"
 	machine_type = "n1-standard-1"
@@ -297,9 +303,8 @@ resource "google_compute_instance" "foobar" {
 	}
 
 	disk {
-		disk = "terraform-test-disk"
+		disk = "${google_compute_disk.foobar.name}"
 		auto_delete = false
-		type = "pd-ssd"
 	}
 
 	network {