diff --git a/core/autoload/fonts.el b/core/autoload/fonts.el
index 1eb0a923a..73f940acf 100644
--- a/core/autoload/fonts.el
+++ b/core/autoload/fonts.el
@@ -20,10 +20,17 @@ If nil, `doom-font' will be used, scaled up by `doom-big-font-increment'. See
 ;;
 ;;; Library
 
-(defun doom--font2xlfd (font)
-  (cond ((stringp font) (aref (font-info font) 0))
-        ((fontp font)   (font-xlfd-name font))
-        ((vectorp font) font)))
+(defun doom--normalize-font (font)
+  (let* ((font (cond ((stringp font) (aref (font-info font) 0))
+                     ((fontp font)   (font-xlfd-name font))
+                     ((vectorp font) (x-compose-font-name font))))
+         (font (x-resolve-font-name font))
+         (font (font-spec :name font)))
+    (unless (font-get font :size)
+      (font-put font :size
+                (font-get (font-spec :name (face-font 'default))
+                          :size)))
+    font))
 
 ;;;###autoload
 (defun doom-adjust-font-size (increment &optional fixed-size-p font-alist)
@@ -52,46 +59,30 @@ Doesn't work in terminal Emacs."
             (if (null increment)
                 (when (get var 'initial-value)
                   (set var (get var 'initial-value))
-                  (put var 'new-size nil)
                   (put var 'initial-value nil)
                   (setq changed t))
-              (let* ((orig-font (or (symbol-value var)
-                                    (face-font face t)
-                                    (with-temp-buffer (face-font face))))
-                     (font (doom--font2xlfd orig-font))
-                     (font (or (and (query-fontset font)
-                                    (if-let (ascii (assq 'ascii (aref (fontset-info font) 2)))
-                                        (nth 2 ascii)
-                                      font))
-                               font))
-                     (dfont (and (stringp font) (x-decompose-font-name font)))
-                     (dfont (if-let* ((remap-font (alist-get var font-alist))
-                                      (remap-xlfd (if (stringp remap-font)
-                                                      (aref (font-info remap-font) 0)
-                                                    (font-xlfd-name remap-font))))
-                                (x-decompose-font-name remap-xlfd)
-                              dfont)))
-                (unless (get var 'initial-value)
-                  (put var 'initial-value orig-font))
-                (unless (vectorp dfont)
-                  (error "Could not decompose %S font: %S" var font))
+              (let* ((original-font (or (symbol-value var)
+                                        (face-font face t)
+                                        (with-temp-buffer (face-font face))))
+                     (font (doom--normalize-font original-font))
+                     (dfont
+                      (or (if-let* ((remap-font (alist-get var font-alist))
+                                    (remap-xlfd (doom--normalize-font remap-font)))
+                              remap-xlfd
+                            (purecopy font))
+                          (error "Could not decompose %s font" var))))
                 (let* ((step      (if fixed-size-p 0 (* increment doom-font-increment)))
-                       (orig-size (string-to-number (aref dfont xlfd-regexp-pixelsize-subnum)))
+                       (orig-size (font-get dfont :size))
                        (new-size  (if fixed-size-p increment (+ orig-size step))))
-                  (unless (> new-size 0)
-                    (error "`%s' font is too small to be reszied (%d)" var new-size))
-                  (if (= orig-size new-size)
-                      (message "Could not resize `%s' for some reason" var)
-                    (put var 'new-size new-size)
-                    (aset dfont xlfd-regexp-pixelsize-subnum (number-to-string new-size))
-                    ;; Set point size & width to "*", so frame width will adjust to new font size
-                    (aset dfont xlfd-regexp-pointsize-subnum "*")
-                    (aset dfont xlfd-regexp-avgwidth-subnum "*")
-                    (setq font (x-compose-font-name dfont))
-                    (unless (x-list-fonts font)
-                      (error "Cannot change font size"))
-                    (set var font)
-                    (setq changed t))))))))
+                  (cond ((<= new-size 0)
+                         (error "`%s' font is too small to be resized (%d)" var new-size))
+                        ((= orig-size new-size)
+                         (user-error "Could not resize `%s' for some reason" var))
+                        ((setq changed t)
+                         (unless (get var 'initial-value)
+                           (put var 'initial-value original-font))
+                         (font-put dfont :size new-size)
+                         (set var dfont)))))))))
     (error
      (ignore-errors (doom-adjust-font-size nil))
      (signal (car e) (cdr e)))))
@@ -154,9 +145,8 @@ Also resizees `doom-variable-pitch-font' and `doom-serif-font'."
   (if doom-big-font
       ;; Use `doom-big-font' in lieu of `doom-font'
       (doom-adjust-font-size
-       (and doom-big-font-mode
-            (aref (x-decompose-font-name (doom--font2xlfd font))
-                  xlfd-regexp-pixelsize-subnum))
+       (if doom-big-font-mode
+           (font-get (doom--normalize-font doom-big-font) :size))
        t `((doom-font . ,doom-big-font)))
     ;; Resize the current font
     (doom-adjust-font-size (if doom-big-font-mode doom-big-font-increment))))