diff --git a/docs/resources/key.md b/docs/resources/key.md
index 41557e2..110f891 100644
--- a/docs/resources/key.md
+++ b/docs/resources/key.md
@@ -17,6 +17,8 @@ resource "random_password" "example" {}
 
 resource "pbkdf2_key" "example" {
   password = random_password.example.result
+  # Output for https://github.com/change-engine/pbkdf-subtle
+  format = "v1{{printf \"%06x\" .Iterations}}{{printf \"%s\" .Key}}"
 }
 ```
 
diff --git a/examples/resources/pbkdf2_key/resource.tf b/examples/resources/pbkdf2_key/resource.tf
index 38797a8..6dc2050 100644
--- a/examples/resources/pbkdf2_key/resource.tf
+++ b/examples/resources/pbkdf2_key/resource.tf
@@ -2,4 +2,6 @@ resource "random_password" "example" {}
 
 resource "pbkdf2_key" "example" {
   password = random_password.example.result
+  # Output for https://github.com/change-engine/pbkdf-subtle
+  format = "v1{{printf \"%06x\" .Iterations}}{{printf \"%s\" .Key}}"
 }
diff --git a/internal/provider/key_resource.go b/internal/provider/key_resource.go
index 7e4f8a5..2508080 100644
--- a/internal/provider/key_resource.go
+++ b/internal/provider/key_resource.go
@@ -48,7 +48,7 @@ func (r *keyResource) Schema(_ context.Context, _ resource.SchemaRequest, resp *
 				MarkdownDescription: "Output format; will additionally be base64 encoded.",
 				Optional:            true,
 				Computed:            true,
-				Default: stringdefault.StaticString("{{.Key}}"),
+				Default: stringdefault.StaticString("{{printf \"%s\" .Key}}"),
 			},
 			"password": schema.StringAttribute{
 				MarkdownDescription: "Base secret.",