diff --git a/tools/code_format/check_format.py b/tools/code_format/check_format.py
index 71645f4cbfd05..af6b1bd43b4b6 100755
--- a/tools/code_format/check_format.py
+++ b/tools/code_format/check_format.py
@@ -523,8 +523,9 @@ def reportError(message):
         match = VERSION_HISTORY_NEW_LINE_REGEX.match(line)
         if not match:
           reportError("Version history line malformed. "
-                      "Does not match VERSION_HISTORY_NEW_LINE_REGEX in check_format.py\n %s" %
-                      line)
+                      "Does not match VERSION_HISTORY_NEW_LINE_REGEX in check_format.py\n %s\n"
+                      "Please use messages in the form 'category: feature explanation.', "
+                      "starting with a lower-cased letter and ending with a period." % line)
         else:
           first_word = match.groups()[0]
           next_word = match.groups()[1]