diff --git a/build/SignToolData.json b/build/SignToolData.json
index 8c629bae65..e00506cc13 100644
--- a/build/SignToolData.json
+++ b/build/SignToolData.json
@@ -222,6 +222,7 @@
     "System.Text.RegularExpressions.dll",
     "System.Threading.AccessControl.dll",
     "System.Threading.dll",
+    "System.Threading.Tasks.Extensions.dll",
     "System.Threading.Overlapped.dll",
     "System.Threading.Tasks.dll",
     "System.Threading.Tasks.Parallel.dll",