diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3695c72..b7aa666 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,3 +9,7 @@
   
 * 0.0.17 -- 2022-02-07
   - update code: 0.0.7
+
+* 0.0.18 -- 2022-02-07
+  - update code: 0.0.8
+  - add tf_module_version variable
diff --git a/lambda.tf b/lambda.tf
index b4486e0..3ff62c4 100644
--- a/lambda.tf
+++ b/lambda.tf
@@ -21,7 +21,10 @@ resource "aws_lambda_function" "lambda" {
   #    version                        = "$LATEST"
 
   environment {
-    variables = local.lambda_environment_variables
+    variables = merge(
+      local.lambda_environment_variables,
+      tomap({ "tf_module_version" = local._module_version }),
+    )
   }
   timeouts {}
   tracing_config {
diff --git a/version.tf b/version.tf
index 80587e5..28a48b4 100644
--- a/version.tf
+++ b/version.tf
@@ -1,3 +1,3 @@
 locals {
-  _module_version = "0.0.17"
+  _module_version = "0.0.18"
 }