diff --git a/crates/languages/src/c/highlights.scm b/crates/languages/src/c/highlights.scm
index 634f8d81c4ad93..a4e728c9be9bff 100644
--- a/crates/languages/src/c/highlights.scm
+++ b/crates/languages/src/c/highlights.scm
@@ -102,13 +102,16 @@
 [
   (true)
   (false)
+] @boolean
+
+[
   (null)
-] @constant
+] @constant.builtin
 
 (identifier) @variable
 
-((identifier) @constant
- (#match? @constant "^_*[A-Z][A-Z\\d_]*$"))
+((identifier) @constant.variable
+ (#match? @constant.variable "^_*[A-Z][A-Z\\d_]*$"))
 
 (call_expression
   function: (identifier) @function)
diff --git a/crates/languages/src/cpp/highlights.scm b/crates/languages/src/cpp/highlights.scm
index 2df9ec2923be3d..89087f4ef726f7 100644
--- a/crates/languages/src/cpp/highlights.scm
+++ b/crates/languages/src/cpp/highlights.scm
@@ -77,8 +77,8 @@ type :(primitive_type) @type.primitive
 (attribute
     name: (identifier) @keyword)
 
-((identifier) @constant
- (#match? @constant "^_*[A-Z][A-Z\\d_]*$"))
+((identifier) @constant.variable
+ (#match? @constant.variable "^_*[A-Z][A-Z\\d_]*$"))
 
 (statement_identifier) @label
 (this) @variable.special
@@ -153,9 +153,12 @@ type :(primitive_type) @type.primitive
 [
   (true)
   (false)
+] @boolean
+
+[
   (null)
   ("nullptr")
-] @constant
+] @constant.builtin
 
 (number_literal) @number