diff --git a/window-purpose-configuration.el b/window-purpose-configuration.el
index 99be102..82bb964 100644
--- a/window-purpose-configuration.el
+++ b/window-purpose-configuration.el
@@ -59,10 +59,7 @@
 
 ;;; Types
 
-;; `purpose-conf' is not an autoload because there is a bug in autoloading
-;; `defclass' in Emacs 24.3. (no problem with Emacs 24.4)
-;; If we decide to drop support for Emacs 24.3, we can make `purpose-conf' an
-;; autoload again.
+;;;###autoload
 (defclass purpose-conf ()
   ((mode-purposes :initarg :mode-purposes
                   :initform '()
@@ -376,8 +373,7 @@ configuration.
 Example:
  (purpose-set-extension-configuration
      :python
-     (purpose-conf \"py\"
-                   :mode-purposes
+     (purpose-conf :mode-purposes
                    '((python-mode . python)
                      (inferior-python-mode . interpreter))))
 
diff --git a/window-purpose-core.el b/window-purpose-core.el
index b27225b..bb30a59 100644
--- a/window-purpose-core.el
+++ b/window-purpose-core.el
@@ -27,6 +27,7 @@
 ;;; Code:
 
 (require 'window-purpose-configuration)
+(eval-when-compile (require 'subr-x))
 
 (defgroup purpose nil
   "purpose-mode configuration"
@@ -190,7 +191,7 @@ FRAME defaults to the selected frame."
   (delete-dups
    (append (list default-purpose)
            (purpose-flatten
-            (mapcar #'purpose-hash-table-values
+            (mapcar #'hash-table-values
                     (append (when purpose-use-default-configuration
                               (list purpose--default-name-purposes
                                     purpose--default-mode-purposes
diff --git a/window-purpose-fixes.el b/window-purpose-fixes.el
index 3df9ffe..9ab105a 100644
--- a/window-purpose-fixes.el
+++ b/window-purpose-fixes.el
@@ -35,30 +35,19 @@
 ;;; when Purpose is on. Solution: make the buffer's window dedicated while
 ;;; executing `compilation-next-error-function'
 
-(define-purpose-compatible-advice 'compilation-next-error-function
-    :around purpose--fix-compilation-next-error
-    (&rest args)
-    "Integrate Purpose and `compilation-next-error-function'.
+(defun purpose--fix-compilation-next-error (oldfun &rest args)
+  "Integrate Purpose and `compilation-next-error-function'.
 Advice that prevents `compilation-next-error-function' from hiding the
 compilation buffer.  This is done by ensuring that the buffer is
 dedicated for the duration of the function.
 This function should be advised around
 `compilation-next-error-function'."
-  ;; new style advice
-  ((let* ((compilation-window (get-buffer-window (marker-buffer (point-marker))))
-          (old-window-dedicated-p (window-dedicated-p compilation-window)))
-     (set-window-dedicated-p compilation-window t)
-     (unwind-protect
-         (apply oldfun args)
-       (set-window-dedicated-p compilation-window old-window-dedicated-p))))
-
-  ;; old style advice
-  ((let* ((compilation-window (get-buffer-window (marker-buffer (point-marker))))
-          (old-window-dedicated-p (window-dedicated-p compilation-window)))
-     (set-window-dedicated-p compilation-window t)
-     (unwind-protect
-         ad-do-it
-       (set-window-dedicated-p compilation-window old-window-dedicated-p)))))
+  (let* ((compilation-window (get-buffer-window (marker-buffer (point-marker))))
+         (old-window-dedicated-p (window-dedicated-p compilation-window)))
+    (set-window-dedicated-p compilation-window t)
+    (unwind-protect
+        (apply oldfun args)
+      (set-window-dedicated-p compilation-window old-window-dedicated-p))))
 
 
 
@@ -72,8 +61,7 @@ This function should be advised around
 
 ;;; Helm's buffers should be ignored, and they should have their own purpose
 (defvar purpose--helm-conf
-  (purpose-conf "helm"
-                :regexp-purposes '(("^\\*Helm" . helm)
+  (purpose-conf :regexp-purposes '(("^\\*Helm" . helm)
                                    ("^\\*helm" . helm)))
   "Purpose configuration for helm.")
 (defun purpose--fix-helm ()
@@ -124,47 +112,33 @@ Override the display and creation of the neotree window.
 When opening files from the neotree window, use Purpose only when
 necessary.
 Note: Don't call this function before `neotree' is loaded."
-  (define-purpose-compatible-advice 'neo-global--create-window
-      :around purpose-fix-neotree-create-window-advice
-      (&rest args)
-      "Override `neo-global--create-window' with `purpose--fix-create-neo-window'.
+  (defun purpose-fix-neotree-create-window-advice (oldfun &rest args)
+    "Override `neo-global--create-window' with `purpose--fix-create-neo-window'.
 When `purpose--active-p' is nil, call original `neo-global--create-window'."
-    ;; new style adivce
-    ((if purpose--active-p
-         (purpose--fix-create-neo-window)
-       (apply oldfun args)))
-    ;; old style advice
-    ((if purpose--active-p
-         (setq ad-return-value (purpose--fix-create-neo-window))
-       ad-do-it)))
-
-  (define-purpose-compatible-advice 'neo-open-file
-      :around purpose-fix-neotree-open-file-advice
-      (full-path &optional arg)
-      "When ARG is nil, make sure Purpose is off while executing `neo-open-file'."
-    ;; new style advice
-    ((if (and purpose--active-p (null arg))
-         (find-file full-path)
-       (without-purpose (funcall oldfun full-path arg))))
-    ;; old style advice
-    ((if (and purpose--active-p (null arg))
-         (setq ad-return-value (find-file full-path))
-       (without-purpose ad-do-it))))
+    (if purpose--active-p
+        (purpose--fix-create-neo-window)
+      (apply oldfun args)))
+
+  (defun purpose-fix-neotree-open-file-advice (oldfun full-path &optional arg)
+    "When ARG is nil, make sure Purpose is off while executing `neo-open-file'."
+    (if (and purpose--active-p (null arg))
+        (find-file full-path)
+      (without-purpose (funcall oldfun full-path arg))))
 
   ;; using purpose 'Neotree, because using 'neotree causes problems with
   ;; `purpose-special-action-sequences' ('neotree is also a function, so
   ;; `purpose--special-action-sequence' will try to call it)
   (purpose-set-extension-configuration
    :neotree
-   (purpose-conf "Neotree" :name-purposes `((,neo-buffer-name . Neotree))))
+   (purpose-conf :name-purposes `((,neo-buffer-name . Neotree))))
   (add-to-list 'purpose-special-action-sequences
                '(Neotree purpose-display-reuse-window-buffer
                          purpose-display-reuse-window-purpose
                          purpose--fix-display-neotree))
-  (purpose-advice-add 'neo-global--create-window
-                      :around 'purpose-fix-neotree-create-window-advice)
-  (purpose-advice-add 'neo-open-file
-                      :around 'purpose-fix-neotree-open-file-advice))
+  (advice-add 'neo-global--create-window
+              :around 'purpose-fix-neotree-create-window-advice)
+  (advice-add 'neo-open-file
+              :around 'purpose-fix-neotree-open-file-advice))
 
 (defun purpose--fix-neotree ()
   "Call `purpose--fix-neotree-1' after `neotree' is loaded."
@@ -181,26 +155,16 @@ When `purpose--active-p' is nil, call original `neo-global--create-window'."
 (defun purpose--fix-org-no-popups-1 ()
   "Make Purpose inactive during some functions that use `org-no-popups'.
 Don't call this function before `org' is loaded."
-  (define-purpose-compatible-advice 'org-switch-to-buffer-other-window
-      :around purpose--fix-org-switch-to-buffer-other-window
-      (&rest args)
-      "Make Purpose inactive during `org-switch-to-buffer-other-window'."
-    ;; new style advice
-    ((without-purpose (apply oldfun args)))
-    ;; old style advice
-    ((without-purpose ad-do-it)))
-  (define-purpose-compatible-advice 'org-get-location
-      :around purpose--fix-org-get-location
-      (&rest args)
-      "Make Purpose inactive during `org-get-location'."
-    ;; new style advice
-    ((without-purpose (apply oldfun args)))
-    ;; old style advice
-    ((without-purpose ad-do-it)))
-  (purpose-advice-add 'org-switch-to-buffer-other-window
-                      :around 'purpose--fix-org-switch-to-buffer-other-window)
-  (purpose-advice-add 'org-get-location
-                      :around 'purpose--fix-org-get-location))
+  (defun purpose--fix-org-switch-to-buffer-other-window (oldfun &rest args)
+    "Make Purpose inactive during `org-switch-to-buffer-other-window'."
+    (without-purpose (apply oldfun args)))
+  (defun purpose--fix-org-get-location (oldfun &rest args)
+    "Make Purpose inactive during `org-get-location'."
+    (without-purpose (apply oldfun args)))
+  (advice-add 'org-switch-to-buffer-other-window
+              :around 'purpose--fix-org-switch-to-buffer-other-window)
+  (advice-add 'org-get-location
+              :around 'purpose--fix-org-get-location))
 
 (defun purpose--fix-org-no-popups ()
   "Call `purpose--fix-org-no-popups-1' after `org' is loaded."
@@ -214,16 +178,11 @@ Don't call this function before `org' is loaded."
 (defun purpose--fix-popwin-1 ()
   "Make Purpose inactive during `popwin:replicate-window-config'.
 Don't call this function before `popwin' is loaded."
-  (define-purpose-compatible-advice 'popwin:replicate-window-config
-      :around purpose--fix-popwin-replicate
-      (&rest args)
-      "Make Purpose inactive during `popwin:replicate-window-config'."
-    ;; new style advice
-    ((without-purpose (apply oldfun args)))
-    ;; old style advice
-    ((without-purpose ad-do-it)))
-  (purpose-advice-add 'popwin:replicate-window-config
-                      :around 'purpose--fix-popwin-replicate))
+  (defun purpose--fix-popwin-replicate (oldfun &rest args)
+    "Make Purpose inactive during `popwin:replicate-window-config'."
+    (without-purpose (apply oldfun args)))
+  (advice-add 'popwin:replicate-window-config
+              :around 'purpose--fix-popwin-replicate))
 
 (defun purpose--fix-popwin ()
   "Call `purpose--fix-popwin-1' after `popwin' is loaded."
@@ -239,7 +198,6 @@ Don't call this function before `popwin' is loaded."
     '(purpose-set-extension-configuration
       :guide-key
       (purpose-conf
-       "guide-key"
        :name-purposes `((,guide-key/guide-buffer-name . guide-key))))))
 
 
@@ -254,7 +212,6 @@ Don't call this function before `popwin' is loaded."
        (purpose-set-extension-configuration
         :which-key
         (purpose-conf
-         "which-key"
          :name-purposes `((,which-key-buffer-name . which-key)))))))
 
 
@@ -264,27 +221,16 @@ Don't call this function before `popwin' is loaded."
   "Let magit-popup display help windows the way it wants."
   (eval-after-load 'magit-popup
     '(progn
-       (define-purpose-compatible-advice 'magit-popup-describe-function
-           :around purpose--fix-magit-popup-help
-           (&rest args)
-           "Make Purpose inactive during `magit-popup-describe-function'."
-         ;; new style advice
-         ((without-purpose (apply oldfun args)))
-         ;; old style advice
-         ((without-purpose ad-do-it)))
-       (define-purpose-compatible-advice 'magit-popup-manpage
-           :around purpose--fix-magit-popup-help
-           (&rest args)
-           "Make Purpose inactive during `magit-popup-manpage'."
-         ;; new style advice
-         ((without-purpose (apply oldfun args)))
-         ;; old style advice
-         ((without-purpose ad-do-it)))
-       (purpose-advice-add 'magit-popup-describe-function
-                           :around 'purpose--fix-magit-popup-help)
-       (purpose-advice-add 'magit-popup-manpage
-                           :around 'purpose--fix-magit-popup-help)
-       )))
+       (defun purpose--fix-magit-popup-help (oldfun &rest args)
+         "Make Purpose inactive during `magit-popup-describe-function'."
+         (without-purpose (apply oldfun args)))
+       (defun purpose--fix-magit-popup-help (oldfun &rest args)
+         "Make Purpose inactive during `magit-popup-manpage'."
+         (without-purpose (apply oldfun args)))
+       (advice-add 'magit-popup-describe-function
+                   :around 'purpose--fix-magit-popup-help)
+       (advice-add 'magit-popup-manpage
+                   :around 'purpose--fix-magit-popup-help))))
 
 ;;; install fixes
 
@@ -303,8 +249,8 @@ are:
 - 'which-key : don't integrate with which-key"
   (interactive)
   (unless (member 'compilation-next-error-function exclude)
-    (purpose-advice-add 'compilation-next-error-function
-                        :around #'purpose--fix-compilation-next-error))
+    (advice-add 'compilation-next-error-function
+                :around #'purpose--fix-compilation-next-error))
   (unless (member 'lv exclude)
     (purpose--fix-hydra-lv))
   (unless (member 'helm exclude)
diff --git a/window-purpose-layout.el b/window-purpose-layout.el
index 6553af0..3f3b387 100644
--- a/window-purpose-layout.el
+++ b/window-purpose-layout.el
@@ -29,6 +29,7 @@
 (require 'cl-lib)
 (require 'ring)
 (require 'window-purpose-core)
+(eval-when-compile (require 'subr-x))
 
 (defconst purpose--built-in-layouts-dir
   (when load-file-name
@@ -233,8 +234,8 @@ WINDOW must be a live window and defaults to the selected one."
   "Get a list of all filenames that end in SUFFIX in DIRECTORY.
 The base filenames without the suffix are returned."
   (cl-loop for filename in (directory-files directory nil nil t)
-           if (purpose--suffix-p suffix filename)
-           collect (purpose--remove-suffix suffix filename)))
+           if (string-suffix-p suffix filename)
+           collect (string-remove-suffix suffix filename)))
 
 (defun purpose--file-with-suffix (name suffix directory)
   "Get file with basename NAME and suffix SUFFIX in DIRECTORY.
diff --git a/window-purpose-switch.el b/window-purpose-switch.el
index f8a6afe..30166c6 100644
--- a/window-purpose-switch.el
+++ b/window-purpose-switch.el
@@ -775,7 +775,7 @@ If ALIST is nil, it is ignored and `purpose--alist' is used instead."
       (let* ((user-action-sequence .user-action-sequence)
              (special-action-sequence (purpose--special-action-sequence buffer
                                                                         alist))
-             (normal-action-sequence (purpose-alist-get
+             (normal-action-sequence (alist-get
                                       (or .action-order
                                           purpose-default-action-order)
                                       purpose-action-sequences))
@@ -933,166 +933,93 @@ treat the funcion(s) as an action sequence."
           fn
         (list fn)))))
 
-(define-purpose-compatible-advice 'display-buffer
-    :around purpose-display-buffer-advice
-    (buffer-or-name &optional action frame)
-    "Update `purpose--alist' when calling `display-buffer'."
-  ;; new style advice
-  ((let ((action-order (purpose-display--action-to-order action))
-         (user-action-sequence (purpose-display--action-to-sequence action))
-         (purpose--alist purpose--alist))
-     (when action-order
-       (setq purpose--alist
-             (purpose-alist-set 'action-order action-order purpose--alist)))
-     (when user-action-sequence
-       (setq purpose--alist (purpose-alist-set 'user-action-sequence
-                                               user-action-sequence
-                                               purpose--alist)))
-     (funcall oldfun buffer-or-name action frame)))
-
-  ;; old style advice
-  ((let* ((action-order (purpose-display--action-to-order action))
-          (user-action-sequence (purpose-display--action-to-sequence action))
-          (purpose--alist purpose--alist))
-     (when action-order
-       (setq purpose--alist
-             (purpose-alist-set 'action-order action-order purpose--alist)))
-     (when user-action-sequence
-       (setq purpose--alist (purpose-alist-set 'user-action-sequence
-                                               user-action-sequence
-                                               purpose--alist)))
-     ad-do-it)))
-
-(define-purpose-compatible-advice 'switch-to-buffer
-    :around purpose-switch-to-buffer-advice
-    (buffer-or-name &optional norecord force-same-window)
-    "Advice for overriding `switch-to-buffer' conditionally.
+(defun purpose-display-buffer-advice
+    (oldfun buffer-or-name &optional action frame)
+  "Update `purpose--alist' when calling `display-buffer'."
+  (let ((action-order (purpose-display--action-to-order action))
+        (user-action-sequence (purpose-display--action-to-sequence action))
+        (purpose--alist purpose--alist))
+    (when action-order
+      (setq purpose--alist
+            (purpose-alist-set 'action-order action-order purpose--alist)))
+    (when user-action-sequence
+      (setq purpose--alist (purpose-alist-set 'user-action-sequence
+                                              user-action-sequence
+                                              purpose--alist)))
+    (funcall oldfun buffer-or-name action frame)))
+
+(defun purpose-switch-to-buffer-advice
+    (oldfun buffer-or-name &optional norecord force-same-window)
+  "Advice for overriding `switch-to-buffer' conditionally.
 If Purpose is active (`purpose--active-p' is non-nil), call
 `purpose-switch-buffer', otherwise call `switch-to-buffer'."
-  ;; new style advice
-  ((purpose-message "switch-to-buffer advice")
-   ;; check the full `purpose--use-action-function-p' here, because
-   ;; if purpose shouldn't be used for some reason (such as
-   ;; `purpose-action-function-ignore-buffer-names'), then we want
-   ;; to fallback to `switch-to-buffer', instead of
-   ;; `display-buffer'
-   (if (purpose--use-action-function-p (window-normalize-buffer-to-switch-to
-                                        buffer-or-name)
-                                       nil)
-       (purpose-switch-buffer buffer-or-name
-                              norecord
-                              ;; when `switch-to-buffer' is called
-                              ;; interactively force-same-window is non-nil,
-                              ;; but want it to be nil, so we check
-                              ;; `called-interactively-p' as well
-                              (and force-same-window
-                                   (not (called-interactively-p 'interactive))
-                                   ;; `ivy--switch-buffer-action' replicates the
-                                   ;; interactive behavior, so handle the same as
-                                   ;; an interactive call
-                                   (not (member 'ivy--switch-buffer-action
-                                                (purpose--function-stack)))))
-     (funcall oldfun buffer-or-name norecord force-same-window)))
-
-  ;; old style advice
-  ((purpose-message "switch-to-buffer advice")
-   (if (purpose--use-action-function-p
-        (window-normalize-buffer-to-switch-to buffer-or-name) nil)
-       (setq ad-return-value
-             (purpose-switch-buffer buffer-or-name
-                                    norecord
-                                    ;; when `switch-to-buffer' is called
-                                    ;; interactively force-same-window is non-nil,
-                                    ;; but want it to be nil, so we check
-                                    ;; `called-interactively-p' as well
-                                    (and force-same-window
-                                         (not (called-interactively-p 'interactive))
-                                         ;; `ivy--switch-buffer-action' replicates the
-                                         ;; interactive behavior, so handle the same as
-                                         ;; an interactive call
-                                         (not (member 'ivy--switch-buffer-action
-                                                      (purpose--function-stack))))))
-     ad-do-it)))
-
-(define-purpose-compatible-advice 'switch-to-buffer-other-window
-    :around purpose-switch-to-buffer-other-window-advice
-    (buffer-or-name &optional norecord)
-    "Advice for overriding `switch-to-buffer-other-window' conditionally.
+  (purpose-message "switch-to-buffer advice")
+  ;; check the full `purpose--use-action-function-p' here, because
+  ;; if purpose shouldn't be used for some reason (such as
+  ;; `purpose-action-function-ignore-buffer-names'), then we want
+  ;; to fallback to `switch-to-buffer', instead of
+  ;; `display-buffer'
+  (if (purpose--use-action-function-p (window-normalize-buffer-to-switch-to
+                                       buffer-or-name)
+                                      nil)
+      (purpose-switch-buffer buffer-or-name
+                             norecord
+                             ;; when `switch-to-buffer' is called
+                             ;; interactively force-same-window is non-nil,
+                             ;; but want it to be nil, so we check
+                             ;; `called-interactively-p' as well
+                             (and force-same-window
+                                  (not (called-interactively-p 'interactive))
+                                  ;; `ivy--switch-buffer-action' replicates the
+                                  ;; interactive behavior, so handle the same as
+                                  ;; an interactive call
+                                  (not (member 'ivy--switch-buffer-action
+                                               (purpose--function-stack)))))
+    (funcall oldfun buffer-or-name norecord force-same-window)))
+
+(defun purpose-switch-to-buffer-other-window-advice
+    (oldfun buffer-or-name &optional norecord)
+  "Advice for overriding `switch-to-buffer-other-window' conditionally.
 If Purpose is active (`purpose--active-p' is non-nil), call
 `purpose-switch-buffer-other-window', otherwise call
 `switch-to-buffer-other-window'."
-  ;; new style advice
-  ((purpose-message "switch-to-buffer-other-window advice")
-   (if purpose--active-p
-       (purpose-switch-buffer-other-window buffer-or-name norecord)
-     (funcall oldfun buffer-or-name norecord)))
-
-  ;; old style advice
-  ((purpose-message "switch-to-buffer-other-window advice")
-   (if purpose--active-p
-       (setq ad-return-value
-             (purpose-switch-buffer-other-window buffer-or-name norecord))
-     ad-do-it)))
-
-(define-purpose-compatible-advice 'switch-to-buffer-other-frame
-    :around purpose-switch-to-buffer-other-frame-advice
-    (buffer-or-name &optional norecord)
-    "Advice for overriding `switch-to-buffer-other-frame' conditionally.
+  (purpose-message "switch-to-buffer-other-window advice")
+  (if purpose--active-p
+      (purpose-switch-buffer-other-window buffer-or-name norecord)
+    (funcall oldfun buffer-or-name norecord)))
+
+(defun purpose-switch-to-buffer-other-frame-advice
+    (oldfun buffer-or-name &optional norecord)
+  "Advice for overriding `switch-to-buffer-other-frame' conditionally.
 If Purpose is active (`purpose--active-p' is non-nil), call
 `purpose-switch-buffer-other-frame', otherwise call
 `switch-to-buffer-other-frame'."
-  ;; new style advice
-  ((purpose-message "switch-to-buffer-other-frame advice")
-   (if purpose--active-p
-       (purpose-switch-buffer-other-frame buffer-or-name norecord)
-     (funcall oldfun buffer-or-name norecord)))
-
-  ;; old style advice
-  ((purpose-message "switch-to-buffer-other-frame advice")
-   (if purpose--active-p
-       (setq ad-return-value
-             (purpose-switch-buffer-other-frame buffer-or-name norecord))
-     ad-do-it)))
-
-(define-purpose-compatible-advice 'pop-to-buffer
-    :around purpose-pop-to-buffer-advice
-    (buffer-or-name &optional action norecord)
-    "Advice for overriding `pop-to-buffer' conditionally.
+  (purpose-message "switch-to-buffer-other-frame advice")
+  (if purpose--active-p
+      (purpose-switch-buffer-other-frame buffer-or-name norecord)
+    (funcall oldfun buffer-or-name norecord)))
+
+(defun purpose-pop-to-buffer-advice
+    (oldfun buffer-or-name &optional action norecord)
+  "Advice for overriding `pop-to-buffer' conditionally.
 If Purpose is active (`purpose--active-p' is non-nil) and ACTION is nil,
 call `purpose-pop-buffer', otherwise call `pop-to-buffer'."
-  ;; new style advice
-  ((purpose-message "pop-to-buffer advice")
-   (if (and purpose--active-p
-            (not action))
-       (purpose-pop-buffer buffer-or-name norecord)
-     (funcall oldfun buffer-or-name action norecord)))
-
-  ;; old style advice
-  ((purpose-message "pop-to-buffer advice")
-   (if (and purpose--active-p
-            (not action))
-       (setq ad-return-value (purpose-pop-buffer buffer-or-name norecord))
-     ad-do-it)))
-
-(define-purpose-compatible-advice 'pop-to-buffer-same-window
-    :around purpose-pop-to-buffer-same-window-advice
-    (buffer-or-name &optional norecord)
-    "Advice for overriding `pop-to-buffer-same-window' conditionally.
+  (purpose-message "pop-to-buffer advice")
+  (if (and purpose--active-p
+           (not action))
+      (purpose-pop-buffer buffer-or-name norecord)
+    (funcall oldfun buffer-or-name action norecord)))
+
+(defun purpose-pop-to-buffer-same-window-advice
+    (oldfun buffer-or-name &optional norecord)
+  "Advice for overriding `pop-to-buffer-same-window' conditionally.
 If Purpose is active (`purpose--active-p' is non-nil), call
 `purpose-pop-buffer-same-window', otherwise call
 `pop-to-buffer-same-window'."
-  ;; new style advice
-  ((purpose-message "pop-to-buffer-same-window advice")
-   (if purpose--active-p
-       (purpose-pop-buffer-same-window buffer-or-name norecord)
-     (funcall oldfun buffer-or-name norecord)))
-
-  ;; old style advice
-  ((purpose-message "pop-to-buffer-same-window advice")
-   (if purpose--active-p
-       (setq ad-return-value
-             (purpose-pop-buffer-same-window buffer-or-name norecord))
-     ad-do-it)))
+  (purpose-message "pop-to-buffer-same-window advice")
+  (if purpose--active-p
+      (purpose-pop-buffer-same-window buffer-or-name norecord)
+    (funcall oldfun buffer-or-name norecord)))
 
 ;; anti-override:
 
diff --git a/window-purpose-utils.el b/window-purpose-utils.el
index 3ae5fb7..55d19df 100644
--- a/window-purpose-utils.el
+++ b/window-purpose-utils.el
@@ -26,8 +26,6 @@
 ;;; Code:
 
 (require 'cl-lib)
-;; subr-x isn't available in 24.3
-(require 'subr-x nil t)
 
 (defcustom purpose-message-on-p nil
   "If non-nil, `purpose-message' will produce a message.
@@ -45,17 +43,6 @@ return the formatted string. FORMAT-STRING and ARGS are passed to
       (apply #'message format-string args)
     (apply #'format format-string args)))
 
-;; define our (limited) version of alist-get
-(defun purpose-alist-get (key alist &optional default _remove)
-  "Get KEY's value in ALIST.
-If no such key, return DEFAULT.
-When setting KEY's value, if the new value is equal to DEFAULT and
-REMOVE is non-nil, then delete the KEY instead."
-  (let ((entry (assq key alist)))
-    (if entry
-        (cdr entry)
-      default)))
-
 (defun purpose-alist-set (key value alist)
   "Set VALUE to be the value associated to KEY in ALIST.
 This doesn't change the original alist, but returns a modified copy."
@@ -102,68 +89,6 @@ Example:
 
 
 
-;;; compatibility layer for advices
-
-(defun purpose-advice-convert-where-arg (where)
-  "Convert WHERE argument from new advice style to old advice style.
-New style is :before, :after, etc.  Old style is 'before, 'after, etc."
-  (unless (keywordp where)
-    (signal 'wrong-type-argument `(keywordp ,where)))
-  (if (eq where :override)
-      'around
-    (intern (mapconcat #'identity (cdr (split-string (symbol-name where) ":")) ":"))))
-
-(defun purpose-advice-new-style-arglist (arglist where)
-  "Convert ARGLIST to new style, according to WHERE.
-If WHERE is :around, add 'oldfun to the beginning of ARGLIST.
-Otherwise, return ARGLIST without changes."
-  (if (eql where :around)
-      (append '(oldfun) arglist)
-    arglist))
-
-(defmacro define-purpose-compatible-advice (symbol where name arglist docstring new-body old-body)
-  "Define advice, using new or old advice style as appropriate.
-SYMBOL and WHERE have the same meaning as in `advice-add'.  NAME
-has the same meaning as FUNCTION argument of `advice-add'.
-ARGLIST has the same meaning as in `defadvice'.  DOCSTRING is the
-advice's documentation.  NEW-BODY is the advice's body if the new
-advice style is available.  OLD-BODY is the advice's body if the
-new advice style is unavailable.
-
-`define-purpose-compatible-advice' properly supports only :around, :before and :after advices."
-  (declare (indent 5) (debug (&define sexp sexp name lambda-list stringp (&rest form) (&rest form))))
-  (if (fboundp 'advice-add)
-      `(defun ,name (,@(purpose-advice-new-style-arglist arglist where))
-     ,docstring
-     ,@new-body)
-    ;; ,(cadr symbol) turns <'foo> into <foo>
-    `(defadvice ,(cadr symbol) (,(purpose-advice-convert-where-arg where) ,name ,arglist)
-       ,docstring
-       ,@old-body)))
-
-(defmacro purpose-advice-add (symbol where name)
-  "Enable advice, using new or old advice style as appropriate.
-SYMBOL, WHERE and NAME have the same meaning as in
-`define-purpose-advice'."
-  (declare (indent nil) (debug 0))
-  (if (fboundp 'advice-add)
-      `(advice-add ,symbol ,where ,name)
-    `(progn
-       (ad-enable-advice ,symbol ',(purpose-advice-convert-where-arg where) ,name)
-       (ad-update ,symbol)
-       (ad-activate ,symbol))))
-
-(defmacro purpose-advice-remove (symbol where name)
-  "Disable advice, using new or old advice style as appropriate.
-SYMBOL, WHERE and NAME have the same meaning as in
-`define-purpose-advice'."
-  (declare (indent nil) (debug 0))
-  (if (fboundp 'advice-remove)
-      `(advice-remove ,symbol ,name)
-    `(progn
-       (ad-disable-advice ,symbol ',(purpose-advice-convert-where-arg where) ,name)
-       (ad-update ,symbol))))
-
 (defun purpose--iter-hash (function table)
   "Like `maphash', but return a list the results of calling FUNCTION
 for each entry in hash-table TABLE."
@@ -175,13 +100,6 @@ for each entry in hash-table TABLE."
              table)
     results))
 
-(defalias 'purpose-hash-table-values
-  (if (fboundp 'hash-table-values)
-    #'hash-table-values
-    (lambda (hash-table)
-      "Return all values in HASH-TABLE."
-        (purpose--iter-hash (lambda (_kk vv) vv) hash-table))))
-
 ;; taken from http://emacs.stackexchange.com/a/7405/6533, credit to Jordon Biondo
 (defun purpose--call-stack ()
   "Return the current call stack frames."
@@ -198,28 +116,5 @@ for each entry in hash-table TABLE."
   "Like `purpose--call-stack' but is a list of only the function names."
   (butlast (mapcar 'cl-second (purpose--call-stack))))
 
-(defalias 'purpose--suffix-p
-  (if (fboundp 'string-suffix-p)
-      #'string-suffix-p
-    ;; taken from string-suffix-p in subr.el in Emacs 24.5.1
-    (lambda (suffix string  &optional ignore-case)
-      "Return non-nil if SUFFIX is a suffix of STRING.
-If IGNORE-CASE is non-nil, the comparison is done without paying
-attention to case differences."
-      (let ((start-pos (- (length string) (length suffix))))
-        (and (>= start-pos 0)
-             (eq t (compare-strings suffix nil nil
-                                    string start-pos nil ignore-case)))))))
-
-(defalias 'purpose--remove-suffix
-  (if (fboundp 'string-remove-suffix)
-      #'string-remove-suffix
-    ;; based on string-remove-suffix in subr-x.el in Emacs 24.5.1
-    (lambda (suffix string)
-      "Remove SUFFIX from STRING if present."
-      (if (purpose--suffix-p suffix string)
-          (substring string 0 (- (length string) (length suffix)))
-        string))))
-
 (provide 'window-purpose-utils)
 ;;; window-purpose-utils.el ends here
diff --git a/window-purpose-x.el b/window-purpose-x.el
index b558ee7..4a1b6f1 100644
--- a/window-purpose-x.el
+++ b/window-purpose-x.el
@@ -70,8 +70,7 @@ All windows are purpose-dedicated.")
 
 ;; the name arg ("purpose-x-code1") is necessary for Emacs 24.3 and older
 (defvar purpose-x-code1-purpose-config
-  (purpose-conf "purpose-x-code1"
-                :mode-purposes
+  (purpose-conf :mode-purposes
                 '((ibuffer-mode . buffers)
                   (dired-mode . dired)
                   (imenu-list-major-mode . ilist))))
@@ -190,13 +189,11 @@ imenu."
 ;;; - `purpose-x-magit-off'
 
 (defvar purpose-x-magit-single-conf
-  (purpose-conf "magit-single"
-                :regexp-purposes '(("^\\*magit" . magit)))
+  (purpose-conf :regexp-purposes '(("^\\*magit" . magit)))
   "Configuration that gives each magit major mode the same purpose.")
 
 (defvar purpose-x-magit-multi-conf
   (purpose-conf
-   "magit-multi"
    :mode-purposes '((magit-diff-mode . magit-diff)
                     (magit-status-mode . magit-status)
                     (magit-log-mode . magit-log)
@@ -384,7 +381,6 @@ The configuration is updated according to
   (interactive)
   (cl-flet ((joiner (x) (cons x 'popup)))
     (let ((conf (purpose-conf
-                 "popwin"
                  :mode-purposes (mapcar #'joiner purpose-x-popwin-major-modes)
                  :name-purposes (mapcar #'joiner purpose-x-popwin-buffer-names)
                  :regexp-purposes (mapcar #'joiner
@@ -673,12 +669,9 @@ window-local buffer lists."
         ;; Unrecord BUFFER in WINDOW.
         (unrecord-window-buffer window buffer)))))
 
-(define-purpose-compatible-advice 'replace-buffer-in-windows
-    :override purpose-x-replace-buffer-in-windows
-    (&optional buffer-or-name)
-    "Override `replace-buffer-in-windows' with a purpose-aware version."
-  ((purpose-x-replace-buffer-in-windows-1 buffer-or-name))
-  ((setq ad-return-value (purpose-x-replace-buffer-in-windows-1 buffer-or-name))))
+(defun purpose-x-replace-buffer-in-windows (&optional buffer-or-name)
+  "Override `replace-buffer-in-windows' with a purpose-aware version."
+  (purpose-x-replace-buffer-in-windows-1 buffer-or-name))
 
 (defun purpose-x-kill-sync ()
   "Synchronize `replace-buffer-in-windows' with `purpose-mode'.
@@ -686,8 +679,8 @@ If `purpose-mode' is enabled, override `replace-buffer-in-windows' with
 `purpose-x-replace-buffer-in-windows'.  If `purpose-mode' is disabled,
 cancel the override of `replace-buffer-in-windows'."
   (if purpose-mode
-      (purpose-advice-add 'replace-buffer-in-windows :override 'purpose-x-replace-buffer-in-windows)
-    (purpose-advice-remove 'replace-buffer-in-windows :override 'purpose-x-replace-buffer-in-windows)))
+      (advice-add 'replace-buffer-in-windows :override 'purpose-x-replace-buffer-in-windows)
+    (advice-remove 'replace-buffer-in-windows 'purpose-x-replace-buffer-in-windows)))
 
 ;;;###autoload
 (defun purpose-x-kill-setup ()
@@ -708,7 +701,7 @@ This is implemented by overriding `replace-buffer-in-windows' with
 (defun purpose-x-kill-unset ()
   "Deactivate purpose-x-kill extension."
   (interactive)
-  (purpose-advice-remove 'replace-buffer-in-windows :override 'purpose-x-replace-buffer-in-windows)
+  (advice-remove 'replace-buffer-in-windows 'purpose-x-replace-buffer-in-windows)
   (remove-hook 'purpose-mode-hook 'purpose-x-kill-sync))
 
 ;;; --- purpose-x-kill ends here ---
diff --git a/window-purpose.el b/window-purpose.el
index b00ed69..4ccad3b 100644
--- a/window-purpose.el
+++ b/window-purpose.el
@@ -7,7 +7,7 @@
 ;; Version: 1.6.1
 ;; Keywords: frames
 ;; Homepage: https://github.com/bmag/emacs-purpose
-;; Package-Requires: ((emacs "24") (cl-lib "0.5") (let-alist "1.0.3") (imenu-list "0.1"))
+;; Package-Requires: ((emacs "25") (imenu-list "0.1"))
 
 ;; This file is not part of GNU Emacs.
 
@@ -272,34 +272,22 @@ Some examples:
 (defun purpose--add-advices ()
   "Add all advices needed for Purpose to work.
 This function is called when `purpose-mode' is activated."
-  (purpose-advice-add 'switch-to-buffer :around
-                      #'purpose-switch-to-buffer-advice)
-  (purpose-advice-add 'switch-to-buffer-other-window :around
-                      #'purpose-switch-to-buffer-other-window-advice)
-  (purpose-advice-add 'switch-to-buffer-other-frame :around
-                      #'purpose-switch-to-buffer-other-frame-advice)
-  (purpose-advice-add 'pop-to-buffer :around
-                      #'purpose-pop-to-buffer-advice)
-  (purpose-advice-add 'pop-to-buffer-same-window :around
-                      #'purpose-pop-to-buffer-same-window-advice)
-  (purpose-advice-add 'display-buffer :around
-                      #'purpose-display-buffer-advice))
+  (advice-add 'switch-to-buffer :around #'purpose-switch-to-buffer-advice)
+  (advice-add 'switch-to-buffer-other-window :around #'purpose-switch-to-buffer-other-window-advice)
+  (advice-add 'switch-to-buffer-other-frame :around #'purpose-switch-to-buffer-other-frame-advice)
+  (advice-add 'pop-to-buffer :around #'purpose-pop-to-buffer-advice)
+  (advice-add 'pop-to-buffer-same-window :around #'purpose-pop-to-buffer-same-window-advice)
+  (advice-add 'display-buffer :around #'purpose-display-buffer-advice))
 
 (defun purpose--remove-advices ()
   "Remove all advices needed for Purpose to work.
 This function is called when `purpose-mode' is deactivated."
-  (purpose-advice-remove 'switch-to-buffer :around
-                         #'purpose-switch-to-buffer-advice)
-  (purpose-advice-remove 'switch-to-buffer-other-window :around
-                         #'purpose-switch-to-buffer-other-window-advice)
-  (purpose-advice-remove 'switch-to-buffer-other-frame :around
-                         #'purpose-switch-to-buffer-other-frame-advice)
-  (purpose-advice-remove 'pop-to-buffer :around
-                         #'purpose-pop-to-buffer-advice)
-  (purpose-advice-remove 'pop-to-buffer-same-window :around
-                         #'purpose-pop-to-buffer-same-window-advice)
-  (purpose-advice-remove 'display-buffer :around
-                         #'purpose-display-buffer-advice))
+  (advice-remove 'switch-to-buffer #'purpose-switch-to-buffer-advice)
+  (advice-remove 'switch-to-buffer-other-window #'purpose-switch-to-buffer-other-window-advice)
+  (advice-remove 'switch-to-buffer-other-frame #'purpose-switch-to-buffer-other-frame-advice)
+  (advice-remove 'pop-to-buffer #'purpose-pop-to-buffer-advice)
+  (advice-remove 'pop-to-buffer-same-window #'purpose-pop-to-buffer-same-window-advice)
+  (advice-remove 'display-buffer #'purpose-display-buffer-advice))
 
 ;;;###autoload
 (define-minor-mode purpose-mode nil