diff --git a/packages/shared/src/relayClient.test.ts b/packages/shared/src/relayClient.test.ts
index 1d556ed6dc30918993d11e788e1c29a1406d3c97..404d765ba74c57b262140ad78e04cb3bbf4ef413 100644
--- a/packages/shared/src/relayClient.test.ts
+++ b/packages/shared/src/relayClient.test.ts
@@ -61,7 +61,10 @@ const makeSpawnerLayer = (commands: Array<string>) =>
     ChildProcessSpawner.make((command) =>
       Effect.sync(() => {
         commands.push(ChildProcess.isStandardCommand(command) ? command.command : "piped-command");
-        return makeHandle();
+        // The pinned Windows executable rejects --version but accepts the version subcommand.
+        return makeHandle(
+          ChildProcess.isStandardCommand(command) && command.args.includes("--version") ? 1 : 0,
+        );
       }),
     ),
   );
diff --git a/packages/shared/src/relayClient.ts b/packages/shared/src/relayClient.ts
index 0a56e45191c221f7a5f37d9698c757c771623d15..3e65b2438d8223e361c0d8763db25aa30b038e89 100644
--- a/packages/shared/src/relayClient.ts
+++ b/packages/shared/src/relayClient.ts
@@ -421,7 +421,7 @@ export const makeCloudflaredRelayClient = Effect.fn("cloudflared.make")(function
           .pipe(wrapInstallFailure("write_failed", "Could not make the relay client executable."));
       }
       yield* report("validating");
-      yield* runCommand(executablePath, ["--version"]).pipe(
+      yield* runCommand(executablePath, ["version"]).pipe(
         wrapInstallFailure("validation_failed", "The downloaded relay client binary did not run."),
       );