diff --git a/monkey/infection_monkey/exploit/caching_agent_repository.py b/monkey/infection_monkey/exploit/caching_agent_repository.py
index 0f86bbd9d..c23aca287 100644
--- a/monkey/infection_monkey/exploit/caching_agent_repository.py
+++ b/monkey/infection_monkey/exploit/caching_agent_repository.py
@@ -5,6 +5,7 @@ from typing import Mapping
 
 import requests
 
+from common import OperatingSystems
 from common.common_consts.timeouts import MEDIUM_REQUEST_TIMEOUT
 
 from . import IAgentRepository
@@ -22,13 +23,13 @@ class CachingAgentRepository(IAgentRepository):
         self._proxies = proxies
         self._lock = threading.Lock()
 
-    def get_agent_binary(self, os: str, architecture: str = None) -> io.BytesIO:
+    def get_agent_binary(self, os: OperatingSystems, architecture: str = None) -> io.BytesIO:
         # If multiple calls to get_agent_binary() are made simultaneously before the result of
         # _download_binary_from_island() is cached, then multiple requests will be sent to the
         # island. Add a mutex in front of the call to _download_agent_binary_from_island() so
         # that only one request per OS will be sent to the island.
         with self._lock:
-            return io.BytesIO(self._download_binary_from_island(os))
+            return io.BytesIO(self._download_binary_from_island(os.value))
 
     @lru_cache(maxsize=None)
     def _download_binary_from_island(self, os: str) -> bytes: