diff --git a/src/configFile.ts b/src/configFile.ts
index 6d5d9fd..9d59f52 100644
--- a/src/configFile.ts
+++ b/src/configFile.ts
@@ -1,8 +1,9 @@
 import fs from 'fs-extra';
+import _ from 'lodash';
 import { resolve } from 'path';
-import yaml from 'yaml';
+import { Document, parse, parseDocument, stringify, YAMLMap } from 'yaml';
 
-import { Config, configSchema } from './Config';
+import { type Config, configSchema } from './Config';
 import { pkgDir } from './pkgDir';
 
 const resolveConfigPath = async (path?: string) => {
@@ -15,7 +16,7 @@ const resolveConfigPath = async (path?: string) => {
 
     if (await fs.exists(resolvedPath)) {
       try {
-        const { configPath } = yaml.parse(
+        const { configPath } = parse(
           await fs.readFile(resolvedPath, 'utf8'),
         ) as Partial<Config>;
 
@@ -34,14 +35,33 @@ const resolveConfigPath = async (path?: string) => {
   return resolvedPath;
 };
 
-export const readConfigFile = async (path?: string) =>
+const readConfigDoc = async (path?: string) =>
+  parseDocument(await fs.readFile(await resolveConfigPath(path), 'utf8'));
+
+export const readConfig = async (path?: string) =>
   configSchema.parse(
-    yaml.parse(await fs.readFile(await resolveConfigPath(path), 'utf8')),
+    parse(await fs.readFile(await resolveConfigPath(path), 'utf8')),
   );
 
-export const writeConfigFile = async (config: Config, path?: string) => {
+export const writeConfig = async (config: Config, path?: string) => {
+  const doc = await readConfigDoc(path);
+
   await fs.writeFile(
     await resolveConfigPath(path),
-    yaml.stringify(config, { doubleQuotedAsJSON: true }),
+    stringify(updateYamlDoc(doc, config), { doubleQuotedAsJSON: true }),
   );
 };
+
+function updateYamlDoc(doc: Document.Parsed, update: object | object[]) {
+  for (const key in update) {
+    const value = _.get(update, key) as object | object[];
+    if (_.isPlainObject(value)) {
+      if (!doc.has(key)) doc.set(key, new YAMLMap());
+      updateYamlDoc(doc.get(key) as Document.Parsed, value);
+    } else {
+      doc.set(key, value);
+    }
+  }
+
+  return doc;
+}
diff --git a/src/parseConfig.ts b/src/parseConfig.ts
index 55456d5..117ddef 100644
--- a/src/parseConfig.ts
+++ b/src/parseConfig.ts
@@ -2,7 +2,7 @@ import { Handlebars } from '@karmaniverous/handlebars';
 import chalk from 'chalk';
 
 import { type Config } from './Config';
-import { readConfigFile } from './configFile';
+import { readConfig } from './configFile';
 import { type ConsoleParams } from './ConsoleParams';
 import { getErrorMessage } from './getErrorMessage';
 
@@ -17,7 +17,7 @@ export const parseConfig = async ({
       process.stdout.write(chalk.black.bold('Parsing config file...'));
 
     // Load & parse config file.
-    config = await readConfigFile(configPath);
+    config = await readConfig(configPath);
 
     // Recursively apply config to itself as a handlebars template.
     let thisPass = JSON.stringify(config);
diff --git a/src/updateConfig.ts b/src/updateConfig.ts
index ee7ace1..40043db 100644
--- a/src/updateConfig.ts
+++ b/src/updateConfig.ts
@@ -4,7 +4,7 @@ import _ from 'lodash';
 import { resolve } from 'path';
 
 import { type Actionable, type Config } from './Config';
-import { readConfigFile, writeConfigFile } from './configFile';
+import { readConfig, writeConfig } from './configFile';
 import { type ConsoleParams } from './ConsoleParams';
 import { getErrorMessage } from './getErrorMessage';
 import { pkgDir } from './pkgDir';
@@ -33,7 +33,7 @@ export const updateConfig = async ({
       );
 
     // Load & parse config file.
-    const config = await readConfigFile(configPath);
+    const config = await readConfig(configPath);
 
     // Validate batch.
     if (!config.batches?.[batch]) {
@@ -66,7 +66,7 @@ export const updateConfig = async ({
     );
 
     // Write updated config to file.
-    await writeConfigFile(config, configPath);
+    await writeConfig(config, configPath);
 
     if (stdOut) process.stdout.write(chalk.black.bold(' Done!\n'));
   } catch (error) {
diff --git a/test/metastructure.yml b/test/metastructure.yml
index 31a5611..d05836d 100644
--- a/test/metastructure.yml
+++ b/test/metastructure.yml
@@ -1,29 +1,29 @@
 # ******************* DO NOT EDIT THIS NOTICE *****************
 # This legal notice is added to every supported source code
-# file at every commit. See the README for more info!                          
+# file at every commit. See the README for more info!
 # *************************************************************
 accounts:
   dev:
-    id: "339712993254"
     email: jscroft+karma.003.dev@gmail.com
     name: Development Account
     organizational_unit: dev
+    id: '339712993254'
   master:
-    id: "891377150698"
+    id: '891377150698'
     email: jscroft+karma.003.master@gmail.com
     name: Master Account
   prod:
-    id: "381491905215"
+    id: '381491905215'
     email: jscroft+karma.003.prod@gmail.com
     name: Production Account
     organizational_unit: prod
   test:
-    id: "381491918621"
+    id: '381491918621'
     email: jscroft+karma.003.test@gmail.com
     name: Testing Account
     organizational_unit: test
   shared_services:
-    id: "975050301644"
+    id: '975050301644'
     email: jscroft+karma.003.shared_services@gmail.com
     name: Shared Services Account
     organizational_unit: infrastructure
@@ -89,14 +89,16 @@ organizational_units:
     name: Workloads OU
 terraform:
   aws_profile: KARMA-INIT
-  aws_version: ">= 5.56.1"
+  aws_version: '>= 5.56.1'
   paths: test
   roles:
     admin: TerraformAdmin
     deployment: TerraformDeployment
     reader: TerraformReader
   state_account: shared_services
-  state_bucket: "{{#if organization.namespace}}{{organization.namespace}}-{{/if}}terraform-state"
+  state_bucket: '{{#if
+    organization.namespace}}{{organization.namespace}}-{{/if}}terraform-state'
   state_key: terraform.tfstate
   state_lock_table: terraform-state-lock
-  terraform_version: ">= 1.9.0"
+  terraform_version: '>= 1.9.0'
+