diff --git a/lib/browser/browser.js b/lib/browser/browser.js
index 0c21a88..a9f413f 100644
--- a/lib/browser/browser.js
+++ b/lib/browser/browser.js
@@ -8,7 +8,7 @@ import { jrefTypeOf } from "../jref/index.js";
 
 
 export const get = async (uri, browser = { _cache: {} }) => {
-  const baseUri = browser.document ? browser.document.baseUri : contextUri();
+  const baseUri = browser.document?.baseUri ?? contextUri();
   uri = resolveIri(uri, baseUri);
   const id = toAbsoluteIri(uri);
   const { fragment } = parseIri(uri);
diff --git a/lib/browser/context-uri.browser.js b/lib/browser/context-uri.browser.js
index 2880ab1..ffd1366 100644
--- a/lib/browser/context-uri.browser.js
+++ b/lib/browser/context-uri.browser.js
@@ -1 +1 @@
-export const contextUri = () => document.location.toString();
+export const contextUri = () => document?.location?.toString() ?? "";
diff --git a/lib/browser/context-uri.js b/lib/browser/context-uri.js
index 2a9cf86..38c916a 100644
--- a/lib/browser/context-uri.js
+++ b/lib/browser/context-uri.js
@@ -1,4 +1,5 @@
 import { cwd } from "node:process";
+import { pathToFileURL } from "node:url";
 
 
-export const contextUri = () => `file://${cwd()}/`;
+export const contextUri = () => pathToFileURL(cwd()) + "/";