diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 8a5b4f1038f..83880d3a1f9 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -21602,7 +21602,7 @@ namespace ts {
             checkMode: CheckMode,
             reportErrors: boolean,
             containingMessageChain: (() => DiagnosticMessageChain | undefined) | undefined,
-        ): ReadonlyArray<Diagnostic> | undefined {
+        ): readonly Diagnostic[] | undefined {
 
             const errorOutputContainer: { errors?: Diagnostic[], skipLogging?: boolean } = { errors: undefined, skipLogging: true };
             if (isJsxOpeningLikeElement(node)) {