diff --git a/src/pointers.ts b/src/pointers.ts
index e2d63c6..365d41c 100644
--- a/src/pointers.ts
+++ b/src/pointers.ts
@@ -1,5 +1,7 @@
+// This is Node-only code due to use of crypto.
+import crypto from 'crypto';
 import path from 'path';
-import { SPEC_URL, toHex } from './util';
+import { SPEC_URL } from './util';
 
 
 export interface PointerInfo {
@@ -74,6 +76,6 @@ export function formatPointerInfo(info: PointerInfo): Buffer {
 
 export async function buildPointerInfo(content: Buffer): Promise<PointerInfo> {
   const size = Buffer.byteLength(content);
-  const hash = await crypto.subtle.digest('SHA-1', content);
-  return { oid: toHex(hash), size };
+  const hash = crypto.createHash('sha256').update(content).digest('hex');
+  return { oid: hash, size };
 }
diff --git a/src/util.ts b/src/util.ts
index 0564b9c..a9a864b 100644
--- a/src/util.ts
+++ b/src/util.ts
@@ -77,14 +77,3 @@ export async function bodyToBuffer(body: Uint8Array[]): Promise<Buffer> {
   }
   return Buffer.from(result.buffer);
 }
-
-
-// Borrowed from Isomorphic Git core, it is not importable.
-export function toHex(buffer: ArrayBuffer): string {
-  let hex = ''
-  for (const byte of new Uint8Array(buffer)) {
-    if (byte < 16) hex += '0'
-    hex += byte.toString(16)
-  }
-  return hex
-}