diff --git a/packages/jmespath/src/Lexer.ts b/packages/jmespath/src/Lexer.ts
index a200b74974..9136311888 100644
--- a/packages/jmespath/src/Lexer.ts
+++ b/packages/jmespath/src/Lexer.ts
@@ -81,7 +81,7 @@ class Lexer {
    *
    * @param current The current character
    */
-  #consumeComparatorSigns = (
+  readonly #consumeComparatorSigns = (
     current: '<' | '>' | '!' | '=' | '|' | '&'
   ): Token => {
     switch (current) {
diff --git a/packages/jmespath/src/Parser.ts b/packages/jmespath/src/Parser.ts
index 8c006cc8e3..c576d5ee2b 100644
--- a/packages/jmespath/src/Parser.ts
+++ b/packages/jmespath/src/Parser.ts
@@ -30,7 +30,7 @@ import { ParsedResult } from './ParsedResult.js';
 import type { Node, Token } from './types.js';
 
 /**
- * Top down operaotr precedence parser for JMESPath.
+ * Top down operator precedence parser for JMESPath.
  *
  * ## References
  * The implementation of this Parser is based on the implementation of
@@ -48,7 +48,7 @@ class Parser {
    * The maximum binding power for a token
    * that can stop a projection.
    */
-  #projectionStop = 10;
+  readonly #projectionStop = 10;
   /**
    * Cache object
    */
@@ -56,7 +56,7 @@ class Parser {
   /**
    * The maximum size of the cache.
    */
-  #maxCacheSize = 128;
+  readonly #maxCacheSize = 128;
   #tokenizer?: Lexer;
   #tokens: Token[];
   #index = 0;
diff --git a/packages/jmespath/src/TreeInterpreter.ts b/packages/jmespath/src/TreeInterpreter.ts
index 385dbab6b3..17be0bd49a 100644
--- a/packages/jmespath/src/TreeInterpreter.ts
+++ b/packages/jmespath/src/TreeInterpreter.ts
@@ -25,7 +25,7 @@ import { isTruthy, sliceArray } from './utils.js';
  * @internal
  */
 class TreeInterpreter {
-  #functions: Functions;
+  readonly #functions: Functions;
 
   /**
    * @param options The options to use for the interpreter.