diff --git a/builtin/providers/aws/resource_aws_instance.go b/builtin/providers/aws/resource_aws_instance.go
index 789297815..4e32dac2c 100644
--- a/builtin/providers/aws/resource_aws_instance.go
+++ b/builtin/providers/aws/resource_aws_instance.go
@@ -487,25 +487,18 @@ func resourceAwsInstanceRead(d *schema.ResourceData, meta interface{}) error {
 
 func resourceAwsInstanceUpdate(d *schema.ResourceData, meta interface{}) error {
 	ec2conn := meta.(*AWSClient).ec2conn
-
-	modify := false
 	opts := new(ec2.ModifyInstance)
 
-	if d.HasChange("source_dest_check") {
-		opts.SetSourceDestCheck = true
-		opts.SourceDestCheck = d.Get("source_dest_check").(bool)
-		modify = true
+	opts.SetSourceDestCheck = true
+	opts.SourceDestCheck = d.Get("source_dest_check").(bool)
+
+	log.Printf("[INFO] Modifying instance %s: %#v", d.Id(), opts)
+	if _, err := ec2conn.ModifyInstance(d.Id(), opts); err != nil {
+		return err
 	}
 
-	if modify {
-		log.Printf("[INFO] Modifying instance %s: %#v", d.Id(), opts)
-		if _, err := ec2conn.ModifyInstance(d.Id(), opts); err != nil {
-			return err
-		}
-
-		// TODO(mitchellh): wait for the attributes we modified to
-		// persist the change...
-	}
+	// TODO(mitchellh): wait for the attributes we modified to
+	// persist the change...
 
 	if err := setTags(ec2conn, d); err != nil {
 		return err
diff --git a/builtin/providers/aws/resource_aws_instance_test.go b/builtin/providers/aws/resource_aws_instance_test.go
index bf59b2a4d..c54751f0e 100644
--- a/builtin/providers/aws/resource_aws_instance_test.go
+++ b/builtin/providers/aws/resource_aws_instance_test.go
@@ -145,10 +145,17 @@ func TestAccAWSInstance_sourceDestCheck(t *testing.T) {
 		CheckDestroy: testAccCheckInstanceDestroy,
 		Steps: []resource.TestStep{
 			resource.TestStep{
-				Config: testAccInstanceConfigSourceDest,
+				Config: testAccInstanceConfigSourceDestDisable,
 				Check: resource.ComposeTestCheckFunc(
-					testAccCheckInstanceExists(
-						"aws_instance.foo", &v),
+					testAccCheckInstanceExists("aws_instance.foo", &v),
+					testCheck(false),
+				),
+			},
+
+			resource.TestStep{
+				Config: testAccInstanceConfigSourceDestEnable,
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckInstanceExists("aws_instance.foo", &v),
 					testCheck(true),
 				),
 			},
@@ -156,8 +163,7 @@ func TestAccAWSInstance_sourceDestCheck(t *testing.T) {
 			resource.TestStep{
 				Config: testAccInstanceConfigSourceDestDisable,
 				Check: resource.ComposeTestCheckFunc(
-					testAccCheckInstanceExists(
-						"aws_instance.foo", &v),
+					testAccCheckInstanceExists("aws_instance.foo", &v),
 					testCheck(false),
 				),
 			},
@@ -388,7 +394,7 @@ resource "aws_instance" "foo" {
 }
 `
 
-const testAccInstanceConfigSourceDest = `
+const testAccInstanceConfigSourceDestEnable = `
 resource "aws_vpc" "foo" {
 	cidr_block = "10.1.0.0/16"
 }