diff --git a/zsh/configs/prompt.zsh b/zsh/configs/prompt.zsh
index 27a01d0..6b779df 100644
--- a/zsh/configs/prompt.zsh
+++ b/zsh/configs/prompt.zsh
@@ -5,5 +5,10 @@ git_prompt_info() {
     echo " %{$fg_bold[green]%}$current_branch%{$reset_color%}"
   fi
 }
+
 setopt promptsubst
-PS1='${SSH_CONNECTION+"%{$fg_bold[green]%}%n@%m:"}%{$fg_bold[blue]%}%c%{$reset_color%}$(git_prompt_info) %# '
+
+# Allow exported PS1 variable to override default prompt.
+if ! env | grep -q '^PS1='; then
+  PS1='${SSH_CONNECTION+"%{$fg_bold[green]%}%n@%m:"}%{$fg_bold[blue]%}%c%{$reset_color%}$(git_prompt_info) %# '
+fi