@@ -1234,23 +1234,26 @@ pub(super) mod types {
         args: &FuncArgs,
         vm: &VirtualMachine,
     ) -> PyResult<()> {
-        let exc_self = exc_self.as_ref();
-        vm.set_attr(
-            exc_self,
-            "filename",
-            vm.unwrap_or_none(args.args.as_slice().get(2).cloned()),
-        )?;
+        os_error_set_attr(&exc_self, args, vm, "filename", 2)?;
         #[cfg(windows)]
-        vm.set_attr(
-            exc_self,
-            "winerror",
-            vm.unwrap_or_none(args.args.as_slice().get(3).cloned()),
-        )?;
-        vm.set_attr(
-            exc_self,
-            "filename2",
-            vm.unwrap_or_none(args.args.as_slice().get(4).cloned()),
-        )?;
+        os_error_set_attr(&exc_self, args, vm, "winerror", 3)?;
+        os_error_set_attr(&exc_self, args, vm, "filename2", 4)?;
+        Ok(())
+    }
+
+    fn os_error_set_attr(
+        exc_self: &PyBaseExceptionRef,
+        args: &FuncArgs,
+        vm: &VirtualMachine,
+        attr_name: &str,
+        arg_idx: usize,
+    ) -> PyResult<()> {
+        let exc_self = exc_self.as_ref();
+
+        if let Some(arg) = args.args.as_slice().get(arg_idx).cloned() {
+            vm.set_attr(exc_self, attr_name, arg)?;
+        }
+
         Ok(())
     }