diff --git a/packages/app/src/Hooks/useImgProxy.ts b/packages/app/src/Hooks/useImgProxy.ts
index 93bd09d..b237081 100644
--- a/packages/app/src/Hooks/useImgProxy.ts
+++ b/packages/app/src/Hooks/useImgProxy.ts
@@ -2,7 +2,7 @@ import * as secp from "@noble/secp256k1";
 import * as base64 from "@protobufjs/base64";
 import { useSelector } from "react-redux";
 import { RootState } from "State/Store";
-import { unwrap } from "Util";
+import { hmacSha256, unwrap } from "Util";
 
 export interface ImgProxySettings {
   url: string;
@@ -19,7 +19,7 @@ export default function useImgProxy() {
   }
 
   async function signUrl(u: string) {
-    const result = await secp.utils.hmacSha256(
+    const result = await hmacSha256(
       secp.utils.hexToBytes(unwrap(settings).key),
       secp.utils.hexToBytes(unwrap(settings).salt),
       te.encode(u)
diff --git a/packages/app/src/Util.ts b/packages/app/src/Util.ts
index 67a3769..fd4a272 100644
--- a/packages/app/src/Util.ts
+++ b/packages/app/src/Util.ts
@@ -1,5 +1,6 @@
 import * as secp from "@noble/secp256k1";
 import { sha256 as hash } from "@noble/hashes/sha256";
+import { hmac } from "@noble/hashes/hmac";
 import { bytesToHex } from "@noble/hashes/utils";
 import { decode as invoiceDecode } from "light-bolt11-decoder";
 import { bech32 } from "bech32";
@@ -453,3 +454,11 @@ export function findTag(e: TaggedRawEvent, tag: string) {
   });
   return maybeTag && maybeTag[1];
 }
+
+export async function hmacSha256(key: Uint8Array, ...messages: Uint8Array[]) {
+  if (window.crypto.subtle) {
+    return await secp.utils.hmacSha256(key, ...messages);
+  } else {
+    return hmac(hash, key, secp.utils.concatBytes(...messages));
+  }
+}