diff --git a/zen-writer.el b/zen-writer.el
index 428c7b6..cea5034 100644
--- a/zen-writer.el
+++ b/zen-writer.el
@@ -35,6 +35,7 @@
 (require 'doom-themes)
 (require 'hl-sentence)
 (defvar doom-theme)
+(defvar custom-enabled-themes)
 
 ;;;###autoload
 (when (and (boundp 'custom-theme-load-path) load-file-name )
@@ -67,16 +68,14 @@
   nil
   ;; body
   (if zen-writer-mode
-      (progn
-        ;; save theme before enabling ZenWriter
-        (setq zen-writer--pre-zen-doom-theme doom-theme)
-        (zen-writer-on))
+      (zen-writer-on)
     (zen-writer-off)))
 
 (defun zen-writer-select-user-theme ()
   "Change the theme back to the theme prior to the Zen Writer theme."
-  (setq doom-theme zen-writer--pre-zen-doom-theme)
-  (load-theme doom-theme t))
+  (when zen-writer--pre-zen-doom-theme
+    (setq doom-theme zen-writer--pre-zen-doom-theme)
+    (load-theme doom-theme t)))
 
 (defun zen-writer-current-hour ()
   "Retrieve current local hour."
@@ -98,12 +97,19 @@
 
 (defun zen-writer-on ()
   "Activate Zen Writer."
+  (when (not zen-writer--pre-zen-doom-theme)
+    ;; save theme before enabling ZenWriter
+    (setq zen-writer--pre-zen-doom-theme
+          (or (when (and custom-enabled-themes (listp custom-enabled-themes))
+                (car custom-enabled-themes))
+              doom-theme)))
   (zen-writer-select-theme)
   (hl-sentence-mode +1))
 
 (defun zen-writer-off ()
   "Deactivate Zen Writer."
   (zen-writer-select-user-theme)
+  (setq zen-writer--pre-zen-doom-theme nil)
   (hl-sentence-mode -1))
 
 ;; Full Zen Writer