diff --git a/libs/path.bash b/libs/path.bash
new file mode 100644
index 0000000..2fa4c10
--- /dev/null
+++ b/libs/path.bash
@@ -0,0 +1,9 @@
+#!/bin/bash
+
+_path_add() {
+    if [ -d "$1" ] && [[ ":$PATH:" != *":$1:"* ]]; then
+        PATH="${PATH:+"$PATH:"}$1"
+    fi
+}
+
+# Source : https://superuser.com/questions/39751/add-directory-to-path-if-its-not-already-there
diff --git a/libs/prompt_command.bash b/libs/prompt_command.bash
new file mode 100644
index 0000000..44e221c
--- /dev/null
+++ b/libs/prompt_command.bash
@@ -0,0 +1,9 @@
+#!/bin/bash
+
+_prompt_command_add() {
+    if [ -n "$1" ] && [[ ":$PROMPT_COMMAND:" != *":$1:"* ]]; then
+        PROMPT_COMMAND="${PROMPT_COMMAND:+"$PROMPT_COMMAND:"}$1"
+    fi
+}
+
+export PROMPT_COMMAND
diff --git a/rc.d/prompt b/rc.d/prompt
index c344d8b..220fb40 100644
--- a/rc.d/prompt
+++ b/rc.d/prompt
@@ -13,7 +13,7 @@ if [ "${POWERLINE}" = "powerline-go" ]; then
 		PS1=$($POWERLINE -jobs "$(jobs -p | wc -l)" -error $? -modules "ssh,host,wsl,user,cwd,direnv,venv,perms,git,jobs,exit,root" -modules-right "docker,docker-context,kube,terraform-workspace,termtitle" -newline)
 	}
 
-	if [ "$TERM" != "linux" ]; then PROMPT_COMMAND="$PROMPT_COMMAND; _update_ps1"; fi
+	if [ "$TERM" != "linux" ]; then _prompt_command_add "_update_ps1" ; fi
 
 elif [ "${POWERLINE}" = "powerline" ]; then