diff --git a/src/runtime/haskell/PGF.hs b/src/runtime/haskell/PGF.hs
index 28438eb0d..b439ef45f 100644
--- a/src/runtime/haskell/PGF.hs
+++ b/src/runtime/haskell/PGF.hs
@@ -19,6 +19,8 @@ module PGF ( PGF2.PGF, readPGF
            , PGF2.Type(..), PGF2.Hypo
            , PGF2.mkType, PGF2.unType
            , PGF2.mkHypo, PGF2.mkDepHypo, PGF2.mkImplHypo
+
+           , PGF2.PGFError(..)
            ) where
 
 import qualified PGF2 as PGF2
diff --git a/src/runtime/haskell/PGF2.hsc b/src/runtime/haskell/PGF2.hsc
index 8fd42f2fb..e36ca39b0 100644
--- a/src/runtime/haskell/PGF2.hsc
+++ b/src/runtime/haskell/PGF2.hsc
@@ -37,9 +37,13 @@ module PGF2 (-- * PGF
              readType,
              mkType, unType,
              mkHypo, mkDepHypo, mkImplHypo,
+
              -- * Concrete syntax
-             ConcName
-            ) where
+             ConcName,
+
+             -- * Exceptions
+             PGFError(..)
+             ) where
 
 import Control.Exception(Exception,throwIO,mask_,bracket)
 import System.IO.Unsafe(unsafePerformIO)