diff --git a/themes/iterate/iterate.theme.bash b/themes/iterate/iterate.theme.bash
index 2031b7fc..cf682a9f 100644
--- a/themes/iterate/iterate.theme.bash
+++ b/themes/iterate/iterate.theme.bash
@@ -52,7 +52,7 @@ function prompt_command() {
     fi
 
     local wrap_char=""
-    [[ ${#new_PS1} -gt $(($COLUMNS/1)) ]] && wrap_char="\n"
+    [[ $COLUMNS && ${#new_PS1} > $(($COLUMNS/1)) ]] && wrap_char="\n"
     PS1="${new_PS1}${green}${wrap_char}→${reset_color} "
 }