diff --git a/macros.tex b/macros.tex
index 565e9ef..147b018 100644
--- a/macros.tex
+++ b/macros.tex
@@ -530,8 +530,8 @@
 \newcommand{\Catchcont}{\keyw{catchcont}}
 \newcommand{\Control}{\keyw{control}}
 \newcommand{\Prompt}{\#}
-\newcommand{\Controlz}{\keyw{control0}}
-\newcommand{\Promptz}{\#_0}
+\newcommand{\Controlz}{\ensuremath{\keyw{control_0}}}
+\newcommand{\Promptz}{\ensuremath{\#_0}}
 \newcommand{\Escape}{\keyw{escape}}
 \newcommand{\shift}{\keyw{shift}}
 \newcommand{\shiftz}{\keyw{shift0}}