diff --git a/silkaj/tx.py b/silkaj/tx.py
index 84f6ba5e8f1ce0ceaa05771a606246215beda510..14898d105a95b8b19da60112c31a03b5dace9382 100644
--- a/silkaj/tx.py
+++ b/silkaj/tx.py
@@ -445,7 +445,7 @@ def checkComment(Comment):
     if len(Comment) > 255:
         message_exit("Error: Comment is too long")
     regex = compile(
-        "^[0-9a-zA-Z\ \-\_\:\/\;\*\[\]\(\)\?\!\^\+\=\@\&\~\#\{\}\|\\\<\>\%\.]*$"
+        "^[0-9a-zA-Z\\ \\-\\_\\:\\/\\;\\*\\[\\]\\(\\)\\?\\!\\^\\+\\=\\@\\&\\~\\#\\{\\}\\|\\\\<\\>\\%\\.]*$"
     )
     if not search(regex, Comment):
         message_exit("Error: the format of the comment is invalid")