diff --git a/api/src/opentrons/hardware_control/module_control.py b/api/src/opentrons/hardware_control/module_control.py
index a2909c0702f..5a062fa5f61 100644
--- a/api/src/opentrons/hardware_control/module_control.py
+++ b/api/src/opentrons/hardware_control/module_control.py
@@ -208,7 +208,7 @@ def get_module_at_port(port: str) -> Optional[modules.ModuleAtPort]:
             if name not in modules.MODULE_HW_BY_NAME:
                 log.warning(f"Unexpected module connected: {name} on {port}")
                 return None
-            return modules.ModuleAtPort(port=f'dev/{port}', name=name)
+            return modules.ModuleAtPort(port=f'/dev/{port}', name=name)
         return None
 
     async def handle_module_appearance(self, event: AionotifyEvent):