diff --git a/core/autoload/popups.el b/core/autoload/popups.el
index b37acc281..344d95ad6 100644
--- a/core/autoload/popups.el
+++ b/core/autoload/popups.el
@@ -186,13 +186,6 @@ window parameter."
     ((or 'left 'right)  (window-width window))
     ((or 'above 'below) (window-height window))))
 
-(defun doom--popup-data (window)
-  (when-let (buffer (window-buffer window))
-    `(,(buffer-name buffer)
-      :file  ,(buffer-file-name buffer)
-      :rules ,(window-parameter window 'popup)
-      :size  ,(doom-popup-size window))))
-
 ;;;###autoload
 (defmacro with-popup-rules! (rules &rest body)
   "TODO"
@@ -218,3 +211,11 @@ window parameter."
         (cl-decf count))
       (when (/= count 0)
         (other-window count)))))
+
+(defun doom--popup-data (window)
+  (unless (doom-popup-property :fixed window)
+    (when-let (buffer (window-buffer window))
+      `(,(buffer-name buffer)
+        :file  ,(buffer-file-name buffer)
+        :rules ,(window-parameter window 'popup)
+        :size  ,(doom-popup-size window)))))
diff --git a/core/core-popups.el b/core/core-popups.el
index ecfe5ecad..c340795a6 100644
--- a/core/core-popups.el
+++ b/core/core-popups.el
@@ -35,7 +35,7 @@
   "The shackle rule that caused this buffer to be recognized as a popup.")
 
 (defvar doom-popup-window-parameters
-  '(:noesc :modeline :autokill :autoclose)
+  '(:noesc :modeline :autokill :autoclose :fixed)
   "A list of window parameters that are set (and cleared) when `doom-popup-mode
 is enabled/disabled.'")
 
@@ -63,7 +63,11 @@ recognized by DOOM's popup system. They are:
             that have an :autokill property.
 
 :autoclose  If non-nil, close popup if ESC is pressed from outside
-            the popup window."
+            the popup window.
+
+:fixed      If non-nil, don't treat this window like a popup. This makes it
+            impervious to being automatically closed or tracked in popup
+            history. Excellent for permanent sidebars."
   (if (cl-every #'listp (mapcar #'doom-unquote rules))
       `(setq shackle-rules (nconc (list ,@rules) shackle-rules))
     `(push (list ,@rules) shackle-rules)))
@@ -509,7 +513,7 @@ the command buffer."
   ;;
   ;; By handing neotree over to shackle, which is better integrated into the
   ;; rest of my config (and persp-mode), this is no longer a problem.
-  (set! :popup " *NeoTree*" :align neo-window-position :size neo-window-width)
+  (set! :popup " *NeoTree*" :align neo-window-position :size neo-window-width :fixed t)
 
   (defun +evil-neotree-display-fn (buf _alist)
     "Hand neotree off to shackle."