diff --git a/package.json b/package.json
index d903e7c..6f7f749 100644
--- a/package.json
+++ b/package.json
@@ -38,7 +38,7 @@
     "fastify": "^4.0.0-rc.2",
     "standard": "^17.0.0",
     "tap": "^16.0.0",
-    "tsd": "^0.20.0"
+    "tsd": "^0.21.0"
   },
   "publishConfig": {
     "access": "public"