diff --git a/autotest/autotest.py b/autotest/autotest.py
index de9d237b..a6cf7e6a 100755
--- a/autotest/autotest.py
+++ b/autotest/autotest.py
@@ -9,7 +9,7 @@ import sys
 logging.basicConfig(level=logging.DEBUG)
 
 def hrule():
-    return "="*int(os.environ.get("COLUMNS", "80"))
+    return "="*int(subprocess.check_output(["tput", "cols"]))
 
 # A "snippet" is something that the user is supposed to do in the workshop.
 # Most of the "snippets" are shell commands.