diff --git a/themes/base.theme.bash b/themes/base.theme.bash
index 50225023..f6d2be0d 100644
--- a/themes/base.theme.bash
+++ b/themes/base.theme.bash
@@ -408,7 +408,8 @@ function safe_append_prompt_command {
     if [[ -n $1 ]] ; then
         case $PROMPT_COMMAND in
             *$1*) ;;
+            "") PROMPT_COMMAND="$1";;
             *) PROMPT_COMMAND="$1;$PROMPT_COMMAND";;
         esac
     fi
-}
\ No newline at end of file
+}