diff --git a/.bash_extra b/.bash_extra
index ade3b19..f546624 100644
--- a/.bash_extra
+++ b/.bash_extra
@@ -12,12 +12,15 @@ source "${HOME}/dotfiles/.bash_ps1"
 # add my scripts to PATH
 PATH=$PATH:"${HOME}/dotfiles/scripts"
 
-### tmux auto attach
-# Check if the user ID is not 0 (root)
-if [ "$EUID" -ne 0 ]; then
-  # then auto attach
-  if command -v tmux &> /dev/null && [ -z "$TMUX" ]; then
-    tmux attach -t default || tmux new -s default
+## check interactive shell https://unix.stackexchange.com/questions/26676/how-to-check-if-a-shell-is-login-interactive-batch
+if [[ $- == *i* ]] ; then
+  ### tmux auto attach
+  # Check if the user ID is not 0 (root)
+  if [ "$EUID" -ne 0 ]; then
+    # then auto attach
+    if command -v tmux &> /dev/null && [ -z "$TMUX" ]; then
+      tmux attach -t default || tmux new -s default
+    fi
   fi
 fi