diff --git a/.tflint_alt.hcl b/.tflint_alt.hcl
index acc0048..b27af21 100644
--- a/.tflint_alt.hcl
+++ b/.tflint_alt.hcl
@@ -12,7 +12,7 @@ plugin "azurerm" {
 
 plugin "basic-ext" {
   enabled     = true
-  version     = "0.2.1"
+  version     = "0.3.1"
   source      = "github.com/Azure/tflint-ruleset-basic-ext"
   signing_key = <<-KEY
 -----BEGIN PGP PUBLIC KEY BLOCK-----
@@ -204,6 +204,10 @@ rule "terraform_output_separate" {
   enabled = true
 }
 
+rule "terraform_variable_nullable_false" {
+  enabled = true
+}
+
 rule "terraform_variable_order" {
   enabled = true
 }