diff --git a/esrally/utils/process.py b/esrally/utils/process.py
index 76dfb5d42..b6d8d9f1c 100644
--- a/esrally/utils/process.py
+++ b/esrally/utils/process.py
@@ -120,7 +120,7 @@ def run_subprocess_with_logging_and_output(
     command_line: str,
     header: Optional[str] = None,
     level: LogLevel = logging.INFO,
-    stdin: Optional[FileId] = None,
+    stdin: Optional[Union[FileId, IO[bytes]]] = None,
     env: Optional[Mapping[str, str]] = None,
     detach: bool = False,
 ) -> subprocess.CompletedProcess: