diff --git a/cps/helper.py b/cps/helper.py
index f7bda696..0b2e50ef 100755
--- a/cps/helper.py
+++ b/cps/helper.py
@@ -266,7 +266,7 @@ def get_valid_filename(value, replace_whitespace=True):
     """
     if value[-1:] == u'.':
         value = value[:-1]+u'_'
-    value = value.replace("/", "_").replace(":", "_")
+    value = value.replace("/", "_").replace(":", "_").strip('\0')
     if use_unidecode:
         value=(unidecode.unidecode(value)).strip()
     else: