diff --git a/modules/lang/cc/autoload.el b/modules/lang/cc/autoload.el
index 9b8a18ef1..000f7eb70 100644
--- a/modules/lang/cc/autoload.el
+++ b/modules/lang/cc/autoload.el
@@ -66,6 +66,45 @@ preceded by the opening brace or a comma (disregarding whitespace in between)."
             (memq (char-before) (list ?, ?\( ?\;))))
     (c-lineup-arglist langlem)))
 
+(defun +cc--re-search-for (regexp)
+  (save-excursion
+    (save-restriction
+      (save-match-data
+        (widen)
+        (goto-char (point-min))
+        (re-search-forward regexp magic-mode-regexp-match-limit t)))))
+
+;;;###autoload
+(defun +cc-c-c++-objc-mode (&optional file)
+  "Sets either `c-mode', `objc-mode' or `c++-mode', whichever is appropriate."
+  (let ((base (file-name-sans-extension buffer-file-name))
+        file)
+    (cond ((file-exists-p! (or (concat base ".cpp")
+                               (concat base ".cc")))
+           (c++-mode))
+          ((or (file-exists-p! (or (concat base ".m")
+                                   (concat base ".mm")))
+               (+cc--re-search-for
+                (concat "^[ \t\r]*\\(?:"
+                        "@\\(?:class\\|interface\\|property\\|end\\)\\_>"
+                        "\\|#import +<Foundation/Foundation.h>"
+                        "\\|[-+] ([a-zA-Z0-9_]+)"
+                        "\\)")))
+           (objc-mode))
+          ((fboundp 'c-or-c++-mode) ; introduced in Emacs 26.1
+           (c-or-c++-mode))
+          ((+cc--re-search-for  ; TODO Remove this along with Emacs 25 support
+            (let ((id "[a-zA-Z0-9_]+") (ws "[ \t\r]+") (ws-maybe "[ \t\r]*"))
+              (concat "^" ws-maybe "\\(?:"
+                      "using"     ws "\\(?:namespace" ws "std;\\|std::\\)"
+                      "\\|" "namespace" "\\(:?" ws id "\\)?" ws-maybe "{"
+                      "\\|" "class"     ws id ws-maybe "[:{\n]"
+                      "\\|" "template"  ws-maybe "<.*>"
+                      "\\|" "#include"  ws-maybe "<\\(?:string\\|iostream\\|map\\)>"
+                      "\\)")))
+           (c++-mode))
+          ((c-mode)))))
+
 
 ;;
 ;; Hooks
diff --git a/modules/lang/cc/config.el b/modules/lang/cc/config.el
index 24a1871a5..9ebedc341 100644
--- a/modules/lang/cc/config.el
+++ b/modules/lang/cc/config.el
@@ -26,37 +26,19 @@ compilation database is present in the project.")
 (def-package! cc-mode
   :commands (c-mode c++-mode objc-mode java-mode)
   :mode ("\\.mm\\'" . objc-mode)
-  :preface
-  ;; The plusses in c++-mode can be annoying to search for ivy/helm (which reads
-  ;; queries as regexps), so wee add these for convenience.
-  (defalias 'cpp-mode 'c++-mode)
-  (defvaralias 'cpp-mode-map 'c++-mode-map)
-
-  (defun +cc-c++-header-file-p ()
-    (and buffer-file-name
-         (equal (file-name-extension buffer-file-name) "h")
-         (or (file-exists-p (expand-file-name
-                             (concat (file-name-sans-extension buffer-file-name)
-                                     ".cpp")))
-             (when-let* ((file (car-safe (projectile-get-other-files
-                                          buffer-file-name
-                                          (projectile-current-project-files)))))
-               (equal (file-name-extension file) "cpp")))))
-
-  (defun +cc-objc-header-file-p ()
-    (and buffer-file-name
-         (equal (file-name-extension buffer-file-name) "h")
-         (re-search-forward "@\\<interface\\>" magic-mode-regexp-match-limit t)))
-
-  (unless (assq '+cc-c++-header-file-p magic-mode-alist)
-    (push '(+cc-c++-header-file-p  . c++-mode)  magic-mode-alist)
-    (push '(+cc-objc-header-file-p . objc-mode) magic-mode-alist))
-
   :init
   (setq-default c-basic-offset tab-width
                 c-backspace-function #'delete-backward-char
                 c-default-style "doom")
 
+  ;; The plusses in c++-mode can be annoying to search for ivy/helm (which reads
+  ;; queries as regexps), so we add these for convenience.
+  (defalias 'cpp-mode 'c++-mode)
+  (defvaralias 'cpp-mode-map 'c++-mode-map)
+
+  ;; Activate `c-mode', `c++-mode' or `objc-mode' depending on heuristics
+  (add-to-list 'auto-mode-alist '("\\.h\\'" . +cc-c-c++-objc-mode))
+
   :config
   (set-electric! '(c-mode c++-mode objc-mode java-mode) :chars '(?\n ?\}))