diff --git a/helm-help.el b/helm-help.el
@@ -24,7 +24,8 @@
   :group 'helm)
 
 (defface helm-helper
-  '((t :inherit helm-header))
+  `((t ,@(and (>= emacs-major-version 27) '(:extend t))
+       :inherit helm-header))
   "Face for Helm help string in minibuffer."
   :group 'helm-help)
 

diff --git a/helm-locate.el b/helm-locate.el
@@ -137,7 +137,8 @@ embedded help for more infos."
     map))
 
 (defface helm-locate-finish
-    '((t (:foreground "Green")))
+  `((t ,@(and (>= emacs-major-version 27) '(:extend t))
+       :foreground "Green"))
   "Face used in mode line when locate process is finish."
   :group 'helm-locate)
 

diff --git a/helm-misc.el b/helm-misc.el
@@ -45,12 +45,14 @@
   :type '(alist :key-type string :value-type function))
 
 (defface helm-time-zone-current
-    '((t (:foreground "green")))
+  `((t ,@(and (>= emacs-major-version 27) '(:extend t))
+       :foreground "green"))
   "Face used to colorize current time in `helm-world-time'."
   :group 'helm-misc)
 
 (defface helm-time-zone-home
-    '((t (:foreground "red")))
+  `((t ,@(and (>= emacs-major-version 27) '(:extend t))
+       :foreground "red"))
   "Face used to colorize home time in `helm-world-time'."
   :group 'helm-misc)
 

diff --git a/helm-mode.el b/helm-mode.el
@@ -189,7 +189,8 @@ and all functions belonging in this list from `minibuffer-setup-hook'.
 This is mainly needed to prevent \"*Completions*\" buffers to popup.")
 
 (defface helm-mode-prefix
-    '((t (:background "red" :foreground "black")))
+  `((t ,@(and (>= emacs-major-version 27) '(:extend t))
+       (:background "red" :foreground "black")))
   "Face used for prefix completion."
   :group 'helm-mode)
 

diff --git a/helm-occur.el b/helm-occur.el
@@ -120,12 +120,14 @@ Note that when using `buffer-substring' initialization will be slower."
 
 
 (defface helm-moccur-buffer
-    '((t (:foreground "DarkTurquoise" :underline t)))
+  `((t ,@(and (>= emacs-major-version 27) '(:extend t))
+       (:foreground "DarkTurquoise" :underline t)))
   "Face used to highlight occur buffer names."
   :group 'helm-occur)
 
 (defface helm-resume-need-update
-    '((t (:background "red")))
+  `((t ,@(and (>= emacs-major-version 27) '(:extend t))
+       (:background "red")))
   "Face used to flash occur buffer when it needs update."
   :group 'helm-occur)
 

diff --git a/helm-sys.el b/helm-sys.el
@@ -28,7 +28,8 @@
   :group 'helm)
 
 (defface helm-top-columns
-    '((t :inherit helm-header))
+  `((t ,@(and (>= emacs-major-version 27) '(:extend t))
+       :inherit helm-header))
   "Face for helm help string in minibuffer."
   :group 'helm-sys)
 

diff --git a/helm-tags.el b/helm-tags.el
@@ -64,8 +64,9 @@ one match."
   :group 'helm-faces)
 
 (defface helm-etags-file
-    '((t (:foreground "Lightgoldenrod4"
-          :underline t)))
+  `((t ,@(and (>= emacs-major-version 27) '(:extend t))
+       :foreground "Lightgoldenrod4"
+       :underline t))
   "Face used to highlight etags filenames."
   :group 'helm-tags-faces)
 

diff --git a/helm-utils.el b/helm-utils.el
@@ -211,12 +211,14 @@ last position is added to the register `helm-save-pos-before-jump-register'.")
 ;;; Faces.
 ;;
 (defface helm-selection-line
-    '((t (:inherit highlight :distant-foreground "black")))
+  `((t ,@(and (>= emacs-major-version 27) '(:extend t))
+       :inherit highlight :distant-foreground "black"))
   "Face used in the `helm-current-buffer' when jumping to a candidate."
   :group 'helm-faces)
 
 (defface helm-match-item
-    '((t (:inherit isearch)))
+  `((t ,@(and (>= emacs-major-version 27) '(:extend t))
+       :inherit isearch))
   "Face used to highlight the item matched in a selected line."
   :group 'helm-faces)
 

diff --git a/helm.el b/helm.el
@@ -883,88 +883,124 @@ You can toggle later `truncate-lines' with
   :group 'helm)
 
 (defface helm-source-header
-  '((((background dark))
+  `((((background dark))
+     ,@(and (>= emacs-major-version 27) '(:extend t))
      :background "#22083397778B"
      :foreground "white"
      :weight bold :height 1.3 :family "Sans Serif")
     (((background light))
+     ,@(and (>= emacs-major-version 27) '(:extend t))
      :background "#abd7f0"
      :foreground "black"
      :weight bold :height 1.3 :family "Sans Serif"))
   "Face for source header in the Helm buffer."
   :group 'helm-faces)
 
 (defface helm-visible-mark
-  '((((min-colors 88) (background dark))
-     (:background "green1" :foreground "black"))
+  `((((min-colors 88) (background dark))
+     ,@(and (>= emacs-major-version 27) '(:extend t))
+     :background "green1"
+     :foreground "black")
     (((background dark))
-     (:background "green" :foreground "black"))
-    (((background light)) :background "#d1f5ea")
+     ,@(and (>= emacs-major-version 27) '(:extend t))
+     :background "green"
+     :foreground "black")
+    (((background light))
+     ,@(and (>= emacs-major-version 27) '(:extend t))
+     :background "#d1f5ea")
     (((min-colors 88))
-     (:background "green1"))
-    (t (:background "green")))
+     ,@(and (>= emacs-major-version 27) '(:extend t))
+     :background "green1")
+    (t ,@(and (>= emacs-major-version 27) '(:extend t))
+       :background "green"))
   "Face for visible mark."
   :group 'helm-faces)
 
 (defface helm-header
-  '((t (:inherit header-line)))
+  `((t ,@(and (>= emacs-major-version 27) '(:extend t))
+       :inherit header-line))
   "Face for header lines in the Helm buffer."
   :group 'helm-faces)
 
 (defface helm-candidate-number
-  '((((background dark)) :background "Yellow" :foreground "black")
-    (((background light)) :background "#faffb5" :foreground "black"))
+  `((((background dark))
+     ,@(and (>= emacs-major-version 27) '(:extend t))
+     :background "Yellow" :foreground "black")
+    (((background light))
+     ,@(and (>= emacs-major-version 27) '(:extend t))
+     :background "#faffb5" :foreground "black"))
   "Face for candidate number in mode-line."
   :group 'helm-faces)
 
 (defface helm-candidate-number-suspended
-  '((t (:inherit helm-candidate-number :inverse-video t)))
+  `((t ,@(and (>= emacs-major-version 27) '(:extend t))
+     :inherit helm-candidate-number :inverse-video t))
   "Face for candidate number in mode-line when Helm is suspended."
   :group 'helm-faces)
 
 (defface helm-selection
-  '((((background dark)) :background "ForestGreen"
+  `((((background dark))
+     ,@(and (>= emacs-major-version 27) '(:extend t))
+     :background "ForestGreen"
      :distant-foreground "black")
-    (((background light)) :background "#b5ffd1"
+    (((background light))
+     ,@(and (>= emacs-major-version 27) '(:extend t))
+     :background "#b5ffd1"
      :distant-foreground "black"))
   "Face for currently selected item in the Helm buffer."
   :group 'helm-faces)
 
 (defface helm-separator
-  '((((background dark)) :foreground "red")
-    (((background light)) :foreground "#ffbfb5"))
+  `((((background dark))
+     ,@(and (>= emacs-major-version 27) '(:extend t))
+     :foreground "red")
+    (((background light))
+     ,@(and (>= emacs-major-version 27) '(:extend t))
+     :foreground "#ffbfb5"))
   "Face for multiline source separator."
   :group 'helm-faces)
 
 (defface helm-action
-  '((t (:underline t)))
+  `((t ,@(and (>= emacs-major-version 27) '(:extend t))
+       :underline t))
   "Face for action lines in the Helm action buffer."
   :group 'helm-faces)
 
 (defface helm-prefarg
-  '((((background dark)) :foreground "green")
-    (((background light)) :foreground "red"))
+  `((((background dark))
+     ,@(and (>= emacs-major-version 27) '(:extend t))
+     :foreground "green")
+    (((background light))
+     ,@(and (>= emacs-major-version 27) '(:extend t))
+     :foreground "red"))
   "Face for showing prefix arg in mode-line."
   :group 'helm-faces)
 
 (defface helm-match
-  '((((background light)) :foreground "#b00000")
-    (((background dark))  :foreground "gold1"))
+  `((((background light))
+     ,@(and (>= emacs-major-version 27) '(:extend t))
+     :foreground "#b00000")
+    (((background dark))
+     ,@(and (>= emacs-major-version 27) '(:extend t))
+     :foreground "gold1"))
   "Face used to highlight matches."
   :group 'helm-faces)
 
 (defface helm-header-line-left-margin
-  '((t (:foreground "black" :background "yellow")))
+  `((t ,@(and (>= emacs-major-version 27) '(:extend t))
+       :foreground "black" :background "yellow"))
   "Face used to highlight helm-header sign in left-margin."
   :group 'helm-faces)
 
 (defface helm-minibuffer-prompt
-  '((t (:inherit minibuffer-prompt)))
+  `((t ,@(and (>= emacs-major-version 27) '(:extend t))
+       :inherit minibuffer-prompt))
   "Face used for the minibuffer/headline prompt (such as Pattern:) in Helm."
   :group 'helm-faces)
 
 (defface helm-eob-line
-  '((t (:inherit default)))
+  `((t ,@(and (>= emacs-major-version 27) '(:extend t))
+       :inherit default))
   "Face for empty line at end of sources in the Helm buffer.
 Allow specifying the height of this line."
   :group 'helm-faces)