diff --git a/themes/brunton/brunton.theme.bash b/themes/brunton/brunton.theme.bash
index baa05788..c0bfd49f 100644
--- a/themes/brunton/brunton.theme.bash
+++ b/themes/brunton/brunton.theme.bash
@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+# shellcheck shell=bash
 
 SCM_THEME_PROMPT_PREFIX=""
 SCM_THEME_PROMPT_SUFFIX=""
@@ -10,16 +10,14 @@ SCM_SVN_CHAR="${bold_cyan}⑆${normal}"
 SCM_HG_CHAR="${bold_red}☿${normal}"
 
 is_vim_shell() {
-	if [ ! -z "$VIMRUNTIME" ]
-	then
+	if [ -n "$VIMRUNTIME" ]; then
 		echo "[${cyan}vim shell${normal}]"
 	fi
 }
 
 scm_prompt() {
 	CHAR=$(scm_char)
-	if [ $CHAR = $SCM_NONE_CHAR ]
-	then
+	if [ "$CHAR" = "$SCM_NONE_CHAR" ]; then
 		return
 	else
 		echo " $(scm_char) (${white}$(scm_prompt_info)${normal})"
@@ -27,7 +25,7 @@ scm_prompt() {
 }
 
 prompt() {
-  PS1="${white}${background_blue} \u${normal}${background_blue}@${red}${background_blue}\h $(clock_prompt) ${reset_color}${normal} $(battery_charge)\n${bold_black}${background_white} \w ${normal}$(scm_prompt)$(is_vim_shell)\n${white}>${normal} "
+	PS1="${white}${background_blue} \u${normal}${background_blue}@${red}${background_blue}\h $(clock_prompt) ${reset_color}${normal} $(battery_charge)\n${bold_black}${background_white} \w ${normal}$(scm_prompt)$(is_vim_shell)\n${white}>${normal} "
 }
 
 THEME_CLOCK_COLOR=${THEME_CLOCK_COLOR:-"$blue$background_white"}