diff --git a/src/runtime/haskell/PGF.hs b/src/runtime/haskell/PGF.hs
index a432aa9bb..1138c9634 100644
--- a/src/runtime/haskell/PGF.hs
+++ b/src/runtime/haskell/PGF.hs
@@ -31,7 +31,7 @@ module PGF(
            languages, abstractName, languageCode,
 
            -- * Types
-           Type, Hypo,
+           Type, Hypo, BindType(..),
            showType, readType,
            mkType, mkHypo, mkDepHypo, mkImplHypo,
            unType,