diff --git a/src/runtime/haskell/PGF2.hsc b/src/runtime/haskell/PGF2.hsc
index 304ade1fd..afe05fc9e 100644
--- a/src/runtime/haskell/PGF2.hsc
+++ b/src/runtime/haskell/PGF2.hsc
@@ -96,7 +96,6 @@ import Foreign.C
 import Control.Exception(mask_,bracket)
 import System.IO.Unsafe(unsafePerformIO)
 import System.Random
-import qualified Foreign.Concurrent as C
 import qualified Data.Map as Map
 import Data.IORef
 import Data.List(intersperse,groupBy)
@@ -114,7 +113,7 @@ readPGF fpath =
   mask_ $ do
     c_db <- withPgfExn "readPGF" (pgf_read_pgf c_fpath p_revision)
     c_revision <- peek p_revision
-    fptr <- C.newForeignPtr c_revision (pgf_free_revision c_db c_revision)
+    fptr <- newForeignPtrEnv pgf_free_revision c_db c_revision
     langs <- getConcretes c_db fptr
     return (PGF c_db fptr langs)
 
@@ -130,7 +129,7 @@ bootNGF pgf_path ngf_path =
   mask_ $ do
     c_db <- withPgfExn "bootNGF" (pgf_boot_ngf c_pgf_path c_ngf_path p_revision)
     c_revision <- peek p_revision
-    fptr <- C.newForeignPtr c_revision (pgf_free_revision c_db c_revision)
+    fptr <- newForeignPtrEnv pgf_free_revision c_db c_revision
     langs <- getConcretes c_db fptr
     return (PGF c_db fptr langs)
 
@@ -143,7 +142,7 @@ readNGF fpath =
   mask_ $ do
     c_db <- withPgfExn "readNGF" (pgf_read_ngf c_fpath p_revision)
     c_revision <- peek p_revision
-    fptr <- C.newForeignPtr c_revision (pgf_free_revision c_db c_revision)
+    fptr <- newForeignPtrEnv pgf_free_revision c_db c_revision
     langs <- getConcretes c_db fptr
     return (PGF c_db fptr langs)
 
@@ -159,7 +158,7 @@ newNGF abs_name mb_fpath =
   mask_ $ do
     c_db <- withPgfExn "newNGF" (pgf_new_ngf c_abs_name c_fpath p_revision)
     c_revision <- peek p_revision
-    fptr <- C.newForeignPtr c_revision (pgf_free_revision c_db c_revision)
+    fptr <- newForeignPtrEnv pgf_free_revision c_db c_revision
     return (PGF c_db fptr Map.empty)
 
 writePGF :: FilePath -> PGF -> IO ()
diff --git a/src/runtime/haskell/PGF2/FFI.hsc b/src/runtime/haskell/PGF2/FFI.hsc
index 01fae9543..74d925a2f 100644
--- a/src/runtime/haskell/PGF2/FFI.hsc
+++ b/src/runtime/haskell/PGF2/FFI.hsc
@@ -63,7 +63,9 @@ foreign import ccall pgf_new_ngf :: Ptr PgfText -> CString -> Ptr (Ptr (PgfRevis
 
 foreign import ccall pgf_write_pgf :: CString -> Ptr PgfDB -> Ptr (PgfRevision PGF) -> Ptr PgfExn -> IO ()
 
-foreign import ccall pgf_free_revision :: Ptr PgfDB -> Ptr (PgfRevision PGF) -> IO ()
+foreign import ccall "pgf_free_revision" pgf_free_revision_ :: Ptr PgfDB -> Ptr (PgfRevision PGF) -> IO ()
+
+foreign import ccall "&pgf_free_revision" pgf_free_revision :: FinalizerEnvPtr PgfDB (PgfRevision PGF)
 
 foreign import ccall pgf_free_concr_revision :: Ptr PgfDB -> Ptr (PgfRevision Concr) -> IO ()
 
diff --git a/src/runtime/haskell/PGF2/Transactions.hsc b/src/runtime/haskell/PGF2/Transactions.hsc
index 4a073686f..7ee0a6962 100644
--- a/src/runtime/haskell/PGF2/Transactions.hsc
+++ b/src/runtime/haskell/PGF2/Transactions.hsc
@@ -24,7 +24,6 @@ import PGF2.Expr
 
 import Foreign
 import Foreign.C
-import qualified Foreign.Concurrent as C
 import Control.Exception
 
 #include <pgf/pgf.h>
@@ -90,19 +89,19 @@ branchPGF_ c_name p (Transaction f) =
       then do ((restore (f (a_db p) c_revision c_exn))
                `catch`
                (\e -> do
-                    pgf_free_revision (a_db p) c_revision
+                    pgf_free_revision_ (a_db p) c_revision
                     throwIO (e :: SomeException)))
               ex_type <- (#peek PgfExn, type) c_exn
               if (ex_type :: (#type PgfExnType)) == (#const PGF_EXN_NONE)
                 then do pgf_commit_revision (a_db p) c_revision c_exn
                         ex_type <- (#peek PgfExn, type) c_exn
                         if (ex_type :: (#type PgfExnType)) == (#const PGF_EXN_NONE)
-                          then do fptr <- C.newForeignPtr c_revision (pgf_free_revision (a_db p) c_revision)
+                          then do fptr <- newForeignPtrEnv pgf_free_revision (a_db p) c_revision
                                   langs <- getConcretes (a_db p) fptr
                                   return (PGF (a_db p) fptr langs)
-                          else do pgf_free_revision (a_db p) c_revision
+                          else do pgf_free_revision_ (a_db p) c_revision
                                   return p
-                else do pgf_free_revision (a_db p) c_revision
+                else do pgf_free_revision_ (a_db p) c_revision
                         return p
       else return p
 
@@ -113,7 +112,7 @@ checkoutPGF p name =
     c_revision <- withPgfExn "checkoutPGF" (pgf_checkout_revision (a_db p) c_name)
     if c_revision == nullPtr
       then return Nothing
-      else do fptr <- C.newForeignPtr c_revision (pgf_free_revision (a_db p) c_revision)
+      else do fptr <- newForeignPtrEnv pgf_free_revision (a_db p) c_revision
               langs <- getConcretes (a_db p) fptr
               return (Just (PGF (a_db p) fptr langs))