diff --git a/verilog-mode.el b/verilog-mode.el
index e4a81f9..5e46a04 100644
--- a/verilog-mode.el
+++ b/verilog-mode.el
@@ -3269,15 +3269,15 @@ See also `verilog-font-lock-extra-types'.")
 (defface verilog-font-lock-translate-off-face
   '((((class color)
       (background light))
-     (:background "gray90" :italic t ))
+     (:background "gray90" :slant italic ))
     (((class color)
       (background dark))
-     (:background "gray10" :italic t ))
+     (:background "gray10" :slant italic ))
     (((class grayscale) (background light))
-     (:foreground "DimGray" :italic t))
+     (:foreground "DimGray" :slant italic))
     (((class grayscale) (background dark))
-     (:foreground "LightGray" :italic t))
-    (t (:italic t)))
+     (:foreground "LightGray" :slant italic))
+    (t (:slant italic)))
   "Font lock mode face used to background highlight translate-off regions."
   :group 'font-lock-highlighting-faces)
 
@@ -3287,11 +3287,11 @@ See also `verilog-font-lock-extra-types'.")
 (defface verilog-font-lock-p1800-face
   '((((class color)
       (background light))
-     (:foreground "DarkOrange3" :bold t ))
+     (:foreground "DarkOrange3" :weight bold ))
     (((class color)
       (background dark))
-     (:foreground "orange1" :bold t ))
-    (t (:italic t)))
+     (:foreground "orange1" :weight bold ))
+    (t (:slant italic)))
   "Font lock mode face used to highlight P1800 keywords."
   :group 'font-lock-highlighting-faces)
 (make-obsolete-variable 'verilog-font-lock-p1800-face nil "27.1")
@@ -3302,11 +3302,11 @@ See also `verilog-font-lock-extra-types'.")
 (defface verilog-font-lock-ams-face
   '((((class color)
       (background light))
-     (:foreground "Purple" :bold t ))
+     (:foreground "Purple" :weight bold ))
     (((class color)
       (background dark))
-     (:foreground "orange1" :bold t ))
-    (t (:italic t)))
+     (:foreground "orange1" :weight bold ))
+    (t (:slant italic)))
   "Font lock mode face used to highlight AMS keywords."
   :group 'font-lock-highlighting-faces)
 
@@ -3316,11 +3316,11 @@ See also `verilog-font-lock-extra-types'.")
 (defface verilog-font-lock-grouping-keywords-face
   '((((class color)
       (background light))
-     (:foreground "Purple" :bold t ))
+     (:foreground "Purple" :weight bold ))
     (((class color)
       (background dark))
-     (:foreground "orange1" :bold t ))
-    (t (:italic t)))
+     (:foreground "orange1" :weight bold ))
+    (t (:slant italic)))
   "Font lock mode face used to highlight verilog grouping keywords."
   :group 'font-lock-highlighting-faces)