diff --git a/builtin/providers/aws/resource_aws_instance.go b/builtin/providers/aws/resource_aws_instance.go
index 14bf045f9..01e42b0c6 100644
--- a/builtin/providers/aws/resource_aws_instance.go
+++ b/builtin/providers/aws/resource_aws_instance.go
@@ -137,6 +137,7 @@ func resourceAwsInstance() *schema.Resource {
 			"block_device": &schema.Schema{
 				Type:     schema.TypeSet,
 				Optional: true,
+				Computed: true,
 				Elem: &schema.Resource{
 					Schema: map[string]*schema.Schema{
 						"device_name": &schema.Schema{