diff --git a/src/calibre/utils/formatter.py b/src/calibre/utils/formatter.py
index fdfd7b77c3..50c08977cd 100644
--- a/src/calibre/utils/formatter.py
+++ b/src/calibre/utils/formatter.py
@@ -82,6 +82,7 @@ class TemplateFormatter(string.Formatter):
 
     format_string_re = re.compile(r'^(.*)\|(.*)\|(.*)$')
     compress_spaces = re.compile(r'\s+')
+    backslash_comma_to_comma = re.compile(r'\\,')
 
     arg_parser = re.Scanner([
                 (r',', lambda x,t: ''),
@@ -123,6 +124,7 @@ class TemplateFormatter(string.Formatter):
                 field = fmt[colon:p]
                 func = self.functions[field]
                 args = self.arg_parser.scan(fmt[p+1:])[0]
+                args = [self.backslash_comma_to_comma.sub(',', a) for a in args]
                 if (func[0] == 0 and (len(args) != 1 or args[0])) or \
                         (func[0] > 0 and func[0] != len(args)):
                     raise ValueError('Incorrect number of arguments for function '+ fmt[0:p])