diff --git a/themes/bira.zsh-theme b/themes/bira.zsh-theme
index ecbea3d9b..4b2853c32 100644
--- a/themes/bira.zsh-theme
+++ b/themes/bira.zsh-theme
@@ -23,7 +23,7 @@ local git_branch='$(git_prompt_info)%{$reset_color%}'
 
 PROMPT="╭─${user_host} ${current_dir} ${rvm_ruby} ${git_branch}
 ╰─%B${user_symbol}%b "
-RPS1="${return_code}"
+RPS1="%B${return_code}%b"
 
 ZSH_THEME_GIT_PROMPT_PREFIX="%{$fg[yellow]%}‹"
 ZSH_THEME_GIT_PROMPT_SUFFIX="› %{$reset_color%}"