diff --git a/Data/ByteString.hs b/Data/ByteString.hs
--- a/Data/ByteString.hs
+++ b/Data/ByteString.hs
@@ -4,6 +4,9 @@
 {- LANGUAGE MagicHash, UnboxedTuples,
             NamedFieldPuns, BangPatterns, RecordWildCards -}
 {-# OPTIONS_HADDOCK prune #-}
+#if __GLASGOW_HASKELL__ >= 701
+{-# LANGUAGE Trustworthy #-}
+#endif
 
 -- |
 -- Module      : Data.ByteString
diff --git a/Data/ByteString/Char8.hs b/Data/ByteString/Char8.hs
--- a/Data/ByteString/Char8.hs
+++ b/Data/ByteString/Char8.hs
@@ -3,6 +3,9 @@
 -- If we could, these are what they would be:
 {- LANGUAGE MagicHash, UnboxedTuples -}
 {-# OPTIONS_HADDOCK prune #-}
+#if __GLASGOW_HASKELL__ >= 701
+{-# LANGUAGE Trustworthy #-}
+#endif
 
 -- |
 -- Module      : Data.ByteString.Char8
diff --git a/Data/ByteString/Fusion.hs b/Data/ByteString/Fusion.hs
--- a/Data/ByteString/Fusion.hs
+++ b/Data/ByteString/Fusion.hs
@@ -1,4 +1,7 @@
 {-# OPTIONS_HADDOCK hide #-}
+#if __GLASGOW_HASKELL__ >= 701
+{-# LANGUAGE Safe #-}
+#endif
 -- |
 -- Module      : Data.ByteString.Fusion
 -- License     : BSD-style
diff --git a/Data/ByteString/Internal.hs b/Data/ByteString/Internal.hs
--- a/Data/ByteString/Internal.hs
+++ b/Data/ByteString/Internal.hs
@@ -68,7 +68,7 @@
 import Foreign.ForeignPtr       (ForeignPtr, withForeignPtr)
 import Foreign.Ptr              (Ptr, FunPtr, plusPtr)
 import Foreign.Storable         (Storable(..))
-import Foreign.C.Types          (CInt, CSize, CULong)
+import Foreign.C.Types          (CInt(..), CSize(..), CULong(..))
 import Foreign.C.String         (CString)
 
 #ifndef __NHC__
diff --git a/Data/ByteString/Lazy.hs b/Data/ByteString/Lazy.hs
--- a/Data/ByteString/Lazy.hs
+++ b/Data/ByteString/Lazy.hs
@@ -1,6 +1,9 @@
 {-# LANGUAGE CPP #-}
 {-# OPTIONS_GHC -fno-warn-incomplete-patterns #-}
 {-# OPTIONS_HADDOCK prune #-}
+#if __GLASGOW_HASKELL__ >= 701
+{-# LANGUAGE Trustworthy #-}
+#endif
 
 -- |
 -- Module      : Data.ByteString.Lazy
diff --git a/Data/ByteString/Lazy/Char8.hs b/Data/ByteString/Lazy/Char8.hs
--- a/Data/ByteString/Lazy/Char8.hs
+++ b/Data/ByteString/Lazy/Char8.hs
@@ -1,5 +1,8 @@
 {-# LANGUAGE CPP #-}
 {-# OPTIONS_HADDOCK prune #-}
+#if __GLASGOW_HASKELL__ >= 701
+{-# LANGUAGE Trustworthy #-}
+#endif
 
 -- |
 -- Module      : Data.ByteString.Lazy.Char8
diff --git a/bytestring.cabal b/bytestring.cabal
--- a/bytestring.cabal
+++ b/bytestring.cabal
@@ -1,5 +1,5 @@
 Name:                bytestring
-Version:             0.9.2.0
+Version:             0.9.2.1
 Synopsis:            Fast, packed, strict and lazy byte arrays with a list interface
 Description:
     A time and space-efficient implementation of byte vectors using