diff --git a/bash_tools/theme_bash.sh b/bash_tools/theme_bash.sh
index 9910eb5..0ca4013 100644
--- a/bash_tools/theme_bash.sh
+++ b/bash_tools/theme_bash.sh
@@ -1,4 +1,8 @@
 
 # display git status
 export GIT_PS1_SHOWDIRTYSTATE=1
+if [[ $(type -t foo) != function ]]; then
+    __git_ps1(){
+    }
+fi
 export PS1=' \[\e[0;32m\]\w\[\e[01;31m\]$(__git_ps1 "(%s)")\[\e[00m\]$ '