diff --git a/tests/baselines/reference/api/tsserverlibrary.d.ts b/tests/baselines/reference/api/tsserverlibrary.d.ts
index a384375b248..ae457551a50 100644
--- a/tests/baselines/reference/api/tsserverlibrary.d.ts
+++ b/tests/baselines/reference/api/tsserverlibrary.d.ts
@@ -2217,6 +2217,7 @@ declare namespace ts {
     }
     interface UniqueESSymbolType extends Type {
         symbol: Symbol;
+        escapedName: __String;
     }
     interface StringLiteralType extends LiteralType {
         value: string;