diff --git a/Build/BuildVersion.hs b/Build/BuildVersion.hs
index 5ae1c4cef7..dbd819fff7 100644
--- a/Build/BuildVersion.hs
+++ b/Build/BuildVersion.hs
@@ -6,6 +6,7 @@
 
 import Build.Version
 
+main :: IO ()
 main = do
 	ver <- getVersion
 	writeVersion ver