diff --git a/glazier/lib/download.py b/glazier/lib/download.py
index 678d870f..7d26dfde 100644
--- a/glazier/lib/download.py
+++ b/glazier/lib/download.py
@@ -297,7 +297,9 @@ def _OpenFileStream(
             url, timeout=TIMEOUT, cafile=self._ca_cert_file
         )
       else:
-        file_stream = urllib.request.urlopen(url, timeout=TIMEOUT)
+        file_stream = urllib.request.urlopen(
+            url, timeout=TIMEOUT, cafile=self._ca_cert_file
+        )
 
     # First attempt failed with HTTPError. Reraise and trigger a retry.
     except urllib.error.HTTPError: