diff --git a/lib/display.sh b/lib/display.sh
index 8a9104b..d1f5c32 100644
--- a/lib/display.sh
+++ b/lib/display.sh
@@ -130,10 +130,12 @@ separator()
 {
     echo -ne "$BYellow"
     local i=0
-    for i in {1..$(( $(tput cols) - 1 ))}; do
+    declare -li length=$(( $(tput cols) - 1 ))
+    for i in $(seq 1 $length); do
         echo -n "-"
     done
     echo -e "$DEFAULTCOL"
+    unset i length
 }
 export -f separator