diff --git a/site-lisp/db-utils.el b/site-lisp/db-utils.el
index a547cae..09c702d 100644
--- a/site-lisp/db-utils.el
+++ b/site-lisp/db-utils.el
@@ -64,28 +64,31 @@ If already in `*ansi-term*' buffer, bury it."
 (defun db/run-or-hide-shell (arg)
   "Opens a shell buffer in new window if not already in one.
   Otherwise, closes the current shell window.  With ARG, switch
-  to `default-directory' first."
+  to `default-directory' of the current buffer first."
   ;; idea to split the current window is from
   ;; http://howardism.org/Technical/Emacs/eshell-fun.html
   (interactive "P")
-  (if (derived-mode-p 'shell-mode)
-      ;; bury buffer; reopen with current working directory if arg is given
-      (progn
-        (bury-buffer)
-        (delete-window)
-        (and arg (db/run-or-hide-shell arg)))
-    (if-let ((shell-window (db/find-window-by-buffer-mode 'shell-mode)))
-        (select-window shell-window)
-      ;; open shell
-      (let ((current-dir (expand-file-name default-directory))
-            (height      (/ (window-total-height) 3)))
-        (shell)
-        (enlarge-window (- height (window-total-height)))
-        (when arg
-          (end-of-line)
-          (comint-kill-input)
-          (insert (format "cd '%s'" current-dir))
-          (comint-send-input))))))
+  (cl-flet ((change-to-shell ()
+              (if-let ((shell-window (db/find-window-by-buffer-mode 'shell-mode)))
+                  (select-window shell-window)
+                ;; open shell in buffer with height of ⅓ of current window
+                (let ((height (/ (window-total-height) 3)))
+                  (shell)
+                  (enlarge-window (- height (window-total-height)))))))
+    (if (not arg)
+        ;; toggle shell window
+        (if (not (derived-mode-p 'shell-mode))
+            (change-to-shell)
+          (bury-buffer)
+          (delete-window))
+
+      ;; unconditionally go to shell, and also change to cwd
+      (let ((current-dir (expand-file-name default-directory)))
+        (change-to-shell)
+        (end-of-line)
+        (comint-kill-input)
+        (insert (format "cd '%s'" current-dir))
+        (comint-send-input)))))
 
 
 ;;; General Utilities