diff --git a/README.md b/README.md
index 3bf1072..5017d79 100644
--- a/README.md
+++ b/README.md
@@ -41,7 +41,7 @@ TypeConf supports different storage backends for configuration values:
 
 #### Browser only:
 
-* **withDOMNode(id: string)** DOM element with encoded `value` attribute
+* **withDOMNode(id: string, attribute?: string)** DOM element with encoded `content` attribute
 
 Backends are queried for existing values in the reverse order that they were added. For example:
 
@@ -124,12 +124,12 @@ conf.getObject('object') === { a: 'a', b: { bb: 'bb' } };
 
 **Node.js only.** Use a configuration file as a source. JSON and YAML (requires [js-yaml](https://www.npmjs.com/package/js-yaml)) are supported.
 
-### withDOMNode(id: string): TypeConf
+### withDOMNode(id: string, attribute?: string): TypeConf
 
-**Browser only.** Use a DOM element with a `value` attribute as a source. The value must be a Base64-encoded JSON string. For example:
+**Browser only.** Use a DOM element as a source. The configuration must be a Base64-encoded JSON string in an attribute of the element (default: `content`). For example:
 
 ```html
-<meta id="conf" value="eyJhIjoiYiJ9" />
+<meta id="conf" content="eyJhIjoiYiJ9" />
 ```
 
 ### set(key: string, value: any): TypeConf
diff --git a/package.json b/package.json
index 7d40b79..50e1427 100644
--- a/package.json
+++ b/package.json
@@ -2,7 +2,7 @@
   "name": "typeconf",
   "version": "0.6.1",
   "description": "A typesafe hierarchical configuration manager for Node.js and the browser.",
-  "browser": "dist/TypeConf.js",
+  "browser": "dist/TypeConfBrowser.js",
   "main": "dist/TypeConfNode.js",
   "types": "./dist/TypeConfNode.d.ts",
   "repository": "https://github.com/mfellner/typeconf",
diff --git a/src/TypeConf.ts b/src/TypeConf.ts
index f1bfb80..888b16b 100644
--- a/src/TypeConf.ts
+++ b/src/TypeConf.ts
@@ -68,10 +68,11 @@ export interface TypeConf {
    *
    * Browser only.
    *
-   * @param id ID attribute of the DOM element.
+   * @param id ID attribute value of the DOM element.
+   * @param attribute Content attribute name of the DOM element (default: 'content').
    * @return This TypeConf instance.
    */
-  withDOMNode(id: string): TypeConf;
+  withDOMNode(id: string, attribute?: string): TypeConf;
 
   /**
    * Set an override value.
diff --git a/src/TypeConfBrowser.ts b/src/TypeConfBrowser.ts
index c28bfa7..466c883 100644
--- a/src/TypeConfBrowser.ts
+++ b/src/TypeConfBrowser.ts
@@ -4,12 +4,12 @@ import TypeConfBase from './TypeConfBase';
 import { createStore, ObjectSupplier } from './util';
 
 export default class TypeConfBrowser extends TypeConfBase {
-  public withDOMNode(id: string): TypeConf {
+  public withDOMNode(id: string, attribute: string = 'content'): TypeConf {
     const element = document.getElementById(id);
-    if (!element || !element.hasAttribute('value')) {
+    if (!element || !element.hasAttribute(attribute)) {
       return this;
     }
-    const encodedString = element.getAttribute('value');
+    const encodedString = element.getAttribute(attribute);
     if (!encodedString) {
       return this;
     }
@@ -17,7 +17,7 @@ export default class TypeConfBrowser extends TypeConfBase {
     try {
       storage = JSON.parse(atob(encodedString));
     } catch (e) {
-      throw new StoreError(`cannot read value of DOM node ${id}`, e);
+      throw new StoreError(`cannot read attribute ${attribute} of DOM node ${id}`, e);
     }
     const store = createStore(new ObjectSupplier(storage));
     this.addStore(store, `__DOM_${id}__`);
diff --git a/src/TypeConfNode.ts b/src/TypeConfNode.ts
index 89afc6e..a896416 100644
--- a/src/TypeConfNode.ts
+++ b/src/TypeConfNode.ts
@@ -61,8 +61,11 @@ export default class TypeConfNode extends TypeConfBase {
       get(name: string) {
         const envName = getEnvName(name);
         const result = process.env[envName];
-        if (result !== undefined) return result;
-        return aggregateContainerValues(process.env, envName, separator, camelCase);
+        if (typeof result !== 'undefined') return result;
+        const aggregate = aggregateContainerValues(process.env, envName, separator, camelCase);
+        if (Object.keys(aggregate).length > 0) {
+          return aggregate;
+        }
       },
       aggregate() {
         // We can only find relevant environment variables if a prefix is specified.
diff --git a/test/TypeConfBrowser.test.ts b/test/TypeConfBrowser.test.ts
index 50674a7..3f6fe93 100644
--- a/test/TypeConfBrowser.test.ts
+++ b/test/TypeConfBrowser.test.ts
@@ -13,7 +13,7 @@ describe('TypeConfBrowser', () => {
     const storage = { number: 42 };
     const element = document.createElement('meta');
     element.setAttribute('id', 'typeconf');
-    element.setAttribute('value', btoa(JSON.stringify(storage)));
+    element.setAttribute('content', btoa(JSON.stringify(storage)));
     document.head.appendChild(element);
 
     const conf = new TypeConfBrowser().withDOMNode('typeconf');
@@ -31,7 +31,7 @@ describe('TypeConfBrowser', () => {
   test('TypeConfBrowser.getString with DOM node with empty value attribute', () => {
     const element = document.createElement('meta');
     element.setAttribute('id', 'typeconf');
-    element.setAttribute('value', '');
+    element.setAttribute('content', '');
     document.head.appendChild(element);
 
     expect(new TypeConfBrowser().withDOMNode('typeconf')).toBeInstanceOf(TypeConfBrowser);
@@ -40,7 +40,7 @@ describe('TypeConfBrowser', () => {
   test('TypeConfBrowser.getString with DOM node should throw', () => {
     const element = document.createElement('meta');
     element.setAttribute('id', 'typeconf');
-    element.setAttribute('value', 'invalid');
+    element.setAttribute('content', 'invalid');
     document.head.appendChild(element);
 
     expect(() => new TypeConfBrowser().withDOMNode('typeconf')).toThrowError(StoreError);
diff --git a/test/TypeConfNode.test.ts b/test/TypeConfNode.test.ts
index 4be63e2..0e122dd 100644
--- a/test/TypeConfNode.test.ts
+++ b/test/TypeConfNode.test.ts
@@ -83,6 +83,11 @@ describe('TypeConfNode', () => {
     expect(conf.getBoolean('object')).toEqual(true);
   });
 
+  test('conf.get with empty env', () => {
+    const conf = new TypeConfNode().withEnv();
+    expect(conf.get('test')).toBeUndefined();
+  });
+
   test('conf.getObject withFile and YAML file', () => {
     const conf = new TypeConfNode().withFile(path.resolve(__dirname, 'conf.yaml'));
     expect(conf.getObject('object')).toEqual({ string: 'string' });