diff --git a/Build/NullSoftInstaller.hs b/Build/NullSoftInstaller.hs
index 162fbfc24d..427507b021 100644
--- a/Build/NullSoftInstaller.hs
+++ b/Build/NullSoftInstaller.hs
@@ -119,6 +119,7 @@ cygwinDlls :: [FilePath]
 cygwinDlls =
 	[ "cygwin1.dll"
 	, "cygasn1-8.dll"
+	, "cygattr-1.dll"
 	, "cygheimbase-1.dll"
 	, "cygroken-18.dll"
 	, "cygcom_err-2.dll"