diff --git a/image/bin/my_init b/image/bin/my_init
index a6ded83..05c0b6a 100755
--- a/image/bin/my_init
+++ b/image/bin/my_init
@@ -20,7 +20,7 @@ LOG_LEVEL_WARN = 1
 LOG_LEVEL_INFO = 2
 LOG_LEVEL_DEBUG = 3
 
-SHENV_NAME_WHITELIST_REGEX = re.compile('[^\w\-_\.]')
+SHENV_NAME_WHITELIST_REGEX = re.compile('\W')
 
 log_level = None
 
@@ -130,6 +130,7 @@ def shquote(s):
 
 
 def sanitize_shenvname(s):
+    """Return string with [0-9a-zA-Z_] characters"""
     return re.sub(SHENV_NAME_WHITELIST_REGEX, "_", s)