diff --git a/lisp/progmodes/cc-langs.el b/lisp/progmodes/cc-langs.el
index 29dff4a..cadbe2f 100644
--- a/lisp/progmodes/cc-langs.el
+++ b/lisp/progmodes/cc-langs.el
@@ -973,7 +973,7 @@ since CC Mode treats every identifier as an expression."
 
       ;; Unary.
       (prefix "++" "--" "+" "-" "!" "~"
-	      ,@(when (c-major-mode-is 'c++-mode) '("not" "compl"))
+	      ,@(when (c-major-mode-is 'c++-mode) '("not" "compl" "alignof" "decltype"))
 	      ,@(when (c-major-mode-is '(c-mode c++-mode))
 		  '("*" "&" "sizeof" "??-"))
 	      ,@(when (c-major-mode-is 'objc-mode)
@@ -1606,7 +1606,7 @@ the appropriate place for that."
 	'("_Bool" "_Complex" "_Imaginary") ; Conditionally defined in C99.
 	(c-lang-const c-primitive-type-kwds))
   c++  (append
-	'("bool" "wchar_t")
+	'("bool" "wchar_t" "char16_t" "char32_t")
 	(c-lang-const c-primitive-type-kwds))
   ;; Objective-C extends C, but probably not the new stuff in C99.
   objc (append
@@ -1676,7 +1676,7 @@ but they don't build a type of themselves.  Unlike the keywords on
 not the type face."
   t    nil
   c    '("const" "restrict" "volatile")
-  c++  '("const" "volatile" "throw")
+  c++  '("const" "constexpr" "volatile" "throw" "thread_local")
   objc '("const" "volatile"))
 
 (c-lang-defconst c-opt-type-modifier-key
@@ -2308,8 +2308,12 @@ This construct is \"<keyword> <expression> :\"."
 (c-lang-defconst c-constant-kwds
   "Keywords for constants."
   t       nil
-  (c c++) '("NULL" ;; Not a keyword, but practically works as one.
+  c       '("NULL" ;; Not a keyword, but practically works as one.
 	    "false" "true")		; Defined in C99.
+  c++     '("NULL" ;; Not a keyword, but practically works as one. Kept for
+                   ;; older code that doesn't use C++11's nullptr.
+	    "false" "true"
+            "nullptr")
   objc    '("nil" "Nil" "YES" "NO" "NS_DURING" "NS_HANDLER" "NS_ENDHANDLER")
   idl     '("TRUE" "FALSE")
   java    '("true" "false" "null") ; technically "literals", not keywords