diff --git a/book/src/themes.md b/book/src/themes.md
index d982dee9a..e3b95c0a7 100644
--- a/book/src/themes.md
+++ b/book/src/themes.md
@@ -179,6 +179,7 @@ We use a similar set of scopes as
   - `parameter` - Function parameters
   - `other`
     - `member` - Fields of composite data types (e.g. structs, unions)
+      - `private` - Private fields that use a unique syntax (currently just ECMAScript-based languages)
 
 - `label`
 
@@ -206,6 +207,7 @@ We use a similar set of scopes as
 - `function`
   - `builtin`
   - `method`
+    - `private` - Private methods that use a unique syntax (currently just ECMAScript-based languages)
   - `macro`
   - `special` (preprocessor in C)
 
diff --git a/runtime/queries/ecma/highlights.scm b/runtime/queries/ecma/highlights.scm
index 07f7dfeda..dc8ce5e73 100644
--- a/runtime/queries/ecma/highlights.scm
+++ b/runtime/queries/ecma/highlights.scm
@@ -29,15 +29,24 @@
   name: (identifier) @function)
 (method_definition
   name: (property_identifier) @function.method)
+(method_definition
+  name: (private_property_identifier) @function.method.private)
 
 (pair
   key: (property_identifier) @function.method
   value: [(function) (arrow_function)])
+(pair
+  key: (private_property_identifier) @function.method.private
+  value: [(function) (arrow_function)])
 
 (assignment_expression
   left: (member_expression
     property: (property_identifier) @function.method)
   right: [(function) (arrow_function)])
+(assignment_expression
+  left: (member_expression
+    property: (private_property_identifier) @function.method.private)
+  right: [(function) (arrow_function)])
 
 (variable_declarator
   name: (identifier) @function
@@ -64,6 +73,9 @@
 (call_expression
   function: (member_expression
     property: (property_identifier) @function.method))
+(call_expression
+  function: (member_expression
+    property: (private_property_identifier) @function.method.private))
 
 ; Variables
 ;----------
@@ -74,6 +86,7 @@
 ;-----------
 
 (property_identifier) @variable.other.member
+(private_property_identifier) @variable.other.member.private
 (shorthand_property_identifier) @variable.other.member
 (shorthand_property_identifier_pattern) @variable.other.member