diff --git a/packages/experimental-utils/package.json b/packages/experimental-utils/package.json
index e94079f0996..5ed24642f44 100644
--- a/packages/experimental-utils/package.json
+++ b/packages/experimental-utils/package.json
@@ -57,7 +57,7 @@
   "typesVersions": {
     "<3.8": {
       "*": [
-        "ts3.4/*"
+        "_ts3.4/*"
       ]
     }
   }