diff --git a/google/resource_compute_interconnect_attachment.go b/google/resource_compute_interconnect_attachment.go
index 42634bcf..4449f4f8 100644
--- a/google/resource_compute_interconnect_attachment.go
+++ b/google/resource_compute_interconnect_attachment.go
@@ -94,6 +94,7 @@ func resourceComputeInterconnectAttachment() *schema.Resource {
 			},
 			"vlan_tag8021q": {
 				Type:     schema.TypeInt,
+				Computed: true,
 				Optional: true,
 				ForceNew: true,
 			},
diff --git a/website/docs/r/compute_interconnect_attachment.html.markdown b/website/docs/r/compute_interconnect_attachment.html.markdown
index 83097671..acc66095 100644
--- a/website/docs/r/compute_interconnect_attachment.html.markdown
+++ b/website/docs/r/compute_interconnect_attachment.html.markdown
@@ -103,7 +103,8 @@ The following arguments are supported:
 
 * `vlan_tag8021q` -
   (Optional)
-  The IEEE 802.1Q VLAN tag for this attachment, in the range 2-4094.
+  The IEEE 802.1Q VLAN tag for this attachment, in the range 2-4094. When
+  using PARTNER type this will be managed upstream.
 
 * `region` -
   (Optional)