diff --git a/packages/oidc-client/src/oidc.ts b/packages/oidc-client/src/oidc.ts
index f2eff47fd..b468a641f 100644
--- a/packages/oidc-client/src/oidc.ts
+++ b/packages/oidc-client/src/oidc.ts
@@ -293,10 +293,13 @@ Please checkout that you are using OIDC hook inside a <OidcProvider configuratio
         });
     }
 
-    async generateDemonstrationOfProofOfPossessionAsync(accessToken:string, url:string, method:string): Promise<string> {
+    async generateDemonstrationOfProofOfPossessionAsync(accessToken:string, url:string, method:string, extras:StringMap= {}): Promise<string> {
 
         const configuration = this.configuration;
-        const claimsExtras = {ath: await base64urlOfHashOfASCIIEncodingAsync(accessToken),};
+        const claimsExtras = {
+            ath: await base64urlOfHashOfASCIIEncodingAsync(accessToken),
+            ...extras
+        };
 
         const serviceWorker = await initWorkerAsync(configuration, this.configurationName);
         let demonstratingProofOfPossessionNonce:string;
diff --git a/packages/oidc-client/src/oidcClient.ts b/packages/oidc-client/src/oidcClient.ts
index 32a3c123c..2e2762014 100644
--- a/packages/oidc-client/src/oidcClient.ts
+++ b/packages/oidc-client/src/oidcClient.ts
@@ -67,8 +67,8 @@ export class OidcClient {
         return this._oidc.configuration;
     }
 
-    async generateDemonstrationOfProofOfPossessionAsync(accessToken:string, url:string, method:string) : Promise<string> {
-        return this._oidc.generateDemonstrationOfProofOfPossessionAsync(accessToken, url, method);
+    async generateDemonstrationOfProofOfPossessionAsync(accessToken:string, url:string, method:string, extras:StringMap= {}) : Promise<string> {
+        return this._oidc.generateDemonstrationOfProofOfPossessionAsync(accessToken, url, method, extras);
     }
 
     async getValidTokenAsync(waitMs = 200, numberWait = 50): Promise<ValidToken> {