diff --git a/aiomysql/connection.py b/aiomysql/connection.py
index 046a9a95..55e88cd4 100644
--- a/aiomysql/connection.py
+++ b/aiomysql/connection.py
@@ -40,7 +40,7 @@
 
 try:
     DEFAULT_USER = getpass.getuser()
-except KeyError:
+except (KeyError, OSError):
     DEFAULT_USER = "unknown"