diff --git a/crates/target_typescript/src/keywords b/crates/target_typescript/src/keywords
index 917affe6..64389e56 100644
--- a/crates/target_typescript/src/keywords
+++ b/crates/target_typescript/src/keywords
@@ -53,6 +53,7 @@ true
 try
 type
 typeof
+undefined
 var
 void
 while