diff --git a/Trace/Hpc/Mix.hs b/Trace/Hpc/Mix.hs
--- a/Trace/Hpc/Mix.hs
+++ b/Trace/Hpc/Mix.hs
@@ -1,10 +1,12 @@
-{-# OPTIONS -cpp #-}
+#if __GLASGOW_HASKELL__ >= 701
+{-# LANGUAGE Trustworthy #-}
+#endif
 ---------------------------------------------------------------
 -- Colin Runciman and Andy Gill, June 2006
 ---------------------------------------------------------------
 
--- |Datatypes and file-access routines for the per-module (.mix)
---  indexes used by Hpc.
+-- | Datatypes and file-access routines for the per-module (.mix)
+-- indexes used by Hpc.
 module Trace.Hpc.Mix
         ( Mix(..)
         , MixEntry
diff --git a/Trace/Hpc/Reflect.hsc b/Trace/Hpc/Reflect.hsc
--- a/Trace/Hpc/Reflect.hsc
+++ b/Trace/Hpc/Reflect.hsc
@@ -1,4 +1,8 @@
-{-# LANGUAGE CPP, ForeignFunctionInterface #-}
+{-# LANGUAGE ForeignFunctionInterface #-}
+#if __GLASGOW_HASKELL__ >= 701
+{-# LANGUAGE Trustworthy #-}
+#endif
+
 module Trace.Hpc.Reflect
   ( clearTix
   , examineTix
diff --git a/Trace/Hpc/Tix.hs b/Trace/Hpc/Tix.hs
--- a/Trace/Hpc/Tix.hs
+++ b/Trace/Hpc/Tix.hs
@@ -1,3 +1,6 @@
+#if __GLASGOW_HASKELL__ >= 701
+{-# LANGUAGE Safe #-}
+#endif
 ------------------------------------------------------------
 -- Andy Gill and Colin Runciman, June 2006
 ------------------------------------------------------------
diff --git a/Trace/Hpc/Util.hs b/Trace/Hpc/Util.hs
--- a/Trace/Hpc/Util.hs
+++ b/Trace/Hpc/Util.hs
@@ -1,3 +1,6 @@
+#if __GLASGOW_HASKELL__ >= 701
+{-# LANGUAGE Safe #-}
+#endif
 -----------------------------------------
 -- Andy Gill and Colin Runciman, June 2006
 ------------------------------------------
diff --git a/hpc.cabal b/hpc.cabal
--- a/hpc.cabal
+++ b/hpc.cabal
@@ -1,5 +1,5 @@
 name:         hpc
-version:      0.5.1.0
+version:      0.5.1.1
 license:      BSD3
 license-file: LICENSE
 author:       Andy Gill
@@ -27,7 +27,7 @@
     if flag(small_base)
         Build-Depends: base       >= 3   && < 5,
                        directory  >= 1   && < 1.2,
-                       old-time   >= 1   && < 1.1,
+                       old-time   >= 1   && < 1.2,
                        containers >= 0.1 && < 0.5
     else
         Build-Depends: base < 3