diff --git a/src/client/streamableHttp.test.ts b/src/client/streamableHttp.test.ts
index ac129e29..9e8efa52 100644
--- a/src/client/streamableHttp.test.ts
+++ b/src/client/streamableHttp.test.ts
@@ -169,11 +169,7 @@ describe("StreamableHTTPClientTransport", () => {
       headers: new Headers()
     });
 
-    // This should not throw an error
-    await transport.terminateSession();
-
-    // The session ID should still be preserved since termination wasn't accepted
-    expect(transport.sessionId).toBe("test-session-id");
+    await expect(transport.terminateSession()).resolves.not.toThrow();
   });
 
   it("should handle 404 response when session expires", async () => {
diff --git a/src/client/streamableHttp.ts b/src/client/streamableHttp.ts
index 72559f35..3462b2ab 100644
--- a/src/client/streamableHttp.ts
+++ b/src/client/streamableHttp.ts
@@ -505,10 +505,7 @@ export class StreamableHTTPClientTransport implements Transport {
         );
       }
 
-      // If session termination was successful, clear our session ID
-      if (response.ok) {
-        this._sessionId = undefined;
-      }
+      this._sessionId = undefined;
     } catch (error) {
       this.onerror?.(error as Error);
       throw error;
diff --git a/src/server/streamableHttp.ts b/src/server/streamableHttp.ts
index 82fcf321..ed52eb77 100644
--- a/src/server/streamableHttp.ts
+++ b/src/server/streamableHttp.ts
@@ -42,7 +42,7 @@ export interface StreamableHTTPServerTransportOptions {
   /**
    * A callback for session initialization events
    * This is called when the server initializes a new session.
-   * Usefult in cases when you need to register multiple mcp sessions
+   * Useful in cases when you need to register multiple mcp sessions
    * and need to keep track of them.
    * @param sessionId The generated session ID
    */