diff --git a/CHANGELOG.md b/CHANGELOG.md
index b76e247..f76c226 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,13 @@
-## 0.1.0 (Unreleased)
+## 0.1.2 (April 2, 2024)
 
-FEATURES:
+* Documentation updates
+
+## 0.1.1 (April 2, 2024)
+
+* Documentation updates
+
+## 0.1.0 (April 2, 2024)
+
+NOTES:
+
+* initial beta release
diff --git a/docs/functions/between.md b/docs/functions/between.md
index 4c19c65..a7de086 100644
--- a/docs/functions/between.md
+++ b/docs/functions/between.md
@@ -29,7 +29,7 @@ run "ebs_volume_size" {
 variable "ebs_volume_size" {
   type = number
   validation {
-    condition     = provider::assert::between(1, 100, aws_ebs_volume.example.size)
+    condition     = provider::assert::between(1, 100, var.ebs_volume_size)
     error_message = "EBS volume size must be between 1 and 100 GiB"
   }
 }
diff --git a/docs/functions/null.md b/docs/functions/null.md
index ac8015a..8808d55 100644
--- a/docs/functions/null.md
+++ b/docs/functions/null.md
@@ -15,10 +15,13 @@ description: |-
 
 ```terraform
 variable "example" {
-  type = string
+  type = object({
+    name  = string
+    value = optional(string)
+  })
   validation {
-    condition     = provider::assert::null(var.example) || length(var.example_variable) > 0
-    error_message = "Must either be a non-empty string or null"
+    condition     = provider::assert::null(var.example.value)
+    error_message = "Value must be null"
   }
 }
 ```
diff --git a/docs/index.md b/docs/index.md
index 8e974bb..8bf472d 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -26,7 +26,7 @@ Define the provider as a `required_provider` to use its functions
 terraform {
   required_providers {
     assert = {
-      source  = "bschaatsbergen/assert"
+      source = "bschaatsbergen/assert"
     }
   }
 }
diff --git a/examples/functions/null/variable.tf b/examples/functions/null/variable.tf
index c08ddf8..667f66d 100644
--- a/examples/functions/null/variable.tf
+++ b/examples/functions/null/variable.tf
@@ -1,7 +1,10 @@
 variable "example" {
-  type = string
+  type = object({
+    name  = string
+    value = optional(string)
+  })
   validation {
-    condition     = provider::assert::null(var.example) || length(var.example_variable) > 0
-    error_message = "Must either be a non-empty string or null"
+    condition     = provider::assert::null(var.example.value)
+    error_message = "Value must be null"
   }
 }
diff --git a/examples/provider/provider.tf b/examples/provider/provider.tf
index ec4b552..0ff417c 100644
--- a/examples/provider/provider.tf
+++ b/examples/provider/provider.tf
@@ -1,7 +1,7 @@
 terraform {
   required_providers {
     assert = {
-      source  = "bschaatsbergen/assert"
+      source = "bschaatsbergen/assert"
     }
   }
 }