diff --git a/package.json b/package.json
index 63fb871..790b5e1 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@modelcontextprotocol/sdk",
-  "version": "1.0.3",
+  "version": "1.0.4",
   "description": "Model Context Protocol implementation for TypeScript",
   "license": "MIT",
   "author": "Anthropic, PBC (https://anthropic.com)",
diff --git a/src/shared/protocol.ts b/src/shared/protocol.ts
index 42cec89..f430b31 100644
--- a/src/shared/protocol.ts
+++ b/src/shared/protocol.ts
@@ -278,7 +278,7 @@ export abstract class Protocol<
   }
 
   private _onprogress(notification: ProgressNotification): void {
-    const { progress, total, progressToken } = notification.params;
+    const { progressToken, ...params } = notification.params;
     const handler = this._progressHandlers.get(Number(progressToken));
     if (handler === undefined) {
       this._onerror(
@@ -289,7 +289,7 @@ export abstract class Protocol<
       return;
     }
 
-    handler({ progress, total });
+    handler(params);
   }
 
   private _onresponse(response: JSONRPCResponse | JSONRPCError): void {