diff --git a/packages/ast-spec/src/base/Range.ts b/packages/ast-spec/src/base/Range.ts
index aae6e5e18703..e78f71e3f747 100644
--- a/packages/ast-spec/src/base/Range.ts
+++ b/packages/ast-spec/src/base/Range.ts
@@ -3,4 +3,4 @@
  * Both numbers are a 0-based index which is the position in the array of source code characters.
  * The first is the start position of the node, the second is the end position of the node.
  */
-export type Range = readonly [number, number];
+export type Range = [number, number];
diff --git a/packages/experimental-utils/src/ts-eslint/Rule.ts b/packages/experimental-utils/src/ts-eslint/Rule.ts
index b023b191604a..bdabc3fe883d 100644
--- a/packages/experimental-utils/src/ts-eslint/Rule.ts
+++ b/packages/experimental-utils/src/ts-eslint/Rule.ts
@@ -81,7 +81,7 @@ interface RuleMetaData<TMessageIds extends string> {
 }
 
 interface RuleFix {
-  range: AST.Range;
+  range: Readonly<AST.Range>;
   text: string;
 }
 
@@ -91,25 +91,25 @@ interface RuleFixer {
     text: string,
   ): RuleFix;
 
-  insertTextAfterRange(range: AST.Range, text: string): RuleFix;
+  insertTextAfterRange(range: Readonly<AST.Range>, text: string): RuleFix;
 
   insertTextBefore(
     nodeOrToken: TSESTree.Node | TSESTree.Token,
     text: string,
   ): RuleFix;
 
-  insertTextBeforeRange(range: AST.Range, text: string): RuleFix;
+  insertTextBeforeRange(range: Readonly<AST.Range>, text: string): RuleFix;
 
   remove(nodeOrToken: TSESTree.Node | TSESTree.Token): RuleFix;
 
-  removeRange(range: AST.Range): RuleFix;
+  removeRange(range: Readonly<AST.Range>): RuleFix;
 
   replaceText(
     nodeOrToken: TSESTree.Node | TSESTree.Token,
     text: string,
   ): RuleFix;
 
-  replaceTextRange(range: AST.Range, text: string): RuleFix;
+  replaceTextRange(range: Readonly<AST.Range>, text: string): RuleFix;
 }
 
 type ReportFixFunction = (