diff --git a/output.py b/output.py
index 9633c0b..dd9fc91 100644
--- a/output.py
+++ b/output.py
@@ -66,6 +66,7 @@ def print_info(txt, default_color=termcolors.ENDC):
 
 def coverage_output(lcov, bcov, length=None):
     if lcov is None or bcov is None:
+        length = length or len(STATUS_UNKNOWN)
         return (length - len(STATUS_UNKNOWN)) * ' ' + status_output(STATUS_UNKNOWN, termcolors.FAIL)
     elif lcov > 90:
         rv = termcolors.OKGREEN + '%3d%% (%3d%%)' % (lcov, bcov) + termcolors.ENDC