diff --git a/hermes_cli/service_manager.py b/hermes_cli/service_manager.py
index 22aa08c4479..b8c2158b8dc 100644
--- a/hermes_cli/service_manager.py
+++ b/hermes_cli/service_manager.py
@@ -143,7 +143,7 @@ def _s6_running() -> bool:
     init, or an unrelated process named ``s6-svscan``).
     """
     try:
-        comm = Path("/proc/1/comm").read_text().strip()
+        comm = Path("/proc/1/comm").read_text(encoding="utf-8").strip()
     except OSError:
         return False
     if comm != "s6-svscan":