diff --git a/common/README.md b/common/README.md
index cf6e832..f70625e 100644
--- a/common/README.md
+++ b/common/README.md
@@ -13,7 +13,6 @@ No requirements.
 
 | Name | Description | Type | Default | Required |
 |------|-------------|------|---------|:--------:|
-| \_module\_version | Module version number | `string` | `"2.0"` | no |
 | access\_log\_bucket | Server Access Logging Bucket ID | `string` | n/a | yes |
 | access\_log\_bucket\_prefix | Access log bucket prefix, to which the bucket name will be appended to make the target\_prefix | `string` | `"s3"` | no |
 | allowed\_cidr | List of allowed source IPs (NOT from within the VPC) | `list(string)` | `[]` | no |
diff --git a/common/resources.tf b/common/resources.tf
index 8404a4c..941cea3 100644
--- a/common/resources.tf
+++ b/common/resources.tf
@@ -23,7 +23,7 @@ locals {
   #    "boc:safeguard" = "title26"
   #  }
   base_tags = {
-    "boc:tf_module_version" = var._module_version
+    "boc:tf_module_version" = local._module_version
     "boc:created_by"        = "terraform"
   }
   # strip spaces, convert to lowercase, make distinct, sort. Remove those not in the _defaults
diff --git a/common/version.tf b/common/version.tf
index c2d950a..d09b354 100644
--- a/common/version.tf
+++ b/common/version.tf
@@ -1,5 +1,3 @@
-variable "_module_version" {
-  description = "Module version number"
-  type        = string
-  default     = "2.0"
+locals {
+  _module_version = "2.0"
 }