diff --git a/sim/run.py b/sim/run.py
index e9436f5eba8c487ffe24e6586fc8f09860baa178..b79533699b5f377eed94fbf6e007bc31e336a333 100755
--- a/sim/run.py
+++ b/sim/run.py
@@ -107,6 +107,8 @@ def _mkmock(fun):
 
 os.listdir = _mkmock(os.listdir)
 os.stat = _mkmock(os.stat)
+os.statvfs = _mkmock(os.statvfs)
+os.mkdir = _mkmock(os.mkdir)
 builtins.open = _mkmock(builtins.open)
 
 orig_stat = os.stat