diff --git a/Control/Concurrent/Thread/Delay.hs b/Control/Concurrent/Thread/Delay.hs
--- a/Control/Concurrent/Thread/Delay.hs
+++ b/Control/Concurrent/Thread/Delay.hs
@@ -1,5 +1,9 @@
 {-# LANGUAGE CPP, NoImplicitPrelude, UnicodeSyntax #-}
 
+#if __GLASGOW_HASKELL__ >= 704
+{-# LANGUAGE Safe #-}
+#endif
+
 -------------------------------------------------------------------------------
 -- |
 -- Module     : Control.Concurrent.Thread.Delay
diff --git a/Control/Concurrent/Timeout.hs b/Control/Concurrent/Timeout.hs
--- a/Control/Concurrent/Timeout.hs
+++ b/Control/Concurrent/Timeout.hs
@@ -4,6 +4,10 @@
            , UnicodeSyntax
   #-}
 
+#if __GLASGOW_HASKELL__ >= 704
+{-# LANGUAGE Safe #-}
+#endif
+
 -------------------------------------------------------------------------------
 -- |
 -- Module     : Control.Concurrent.Timeout
diff --git a/unbounded-delays.cabal b/unbounded-delays.cabal
--- a/unbounded-delays.cabal
+++ b/unbounded-delays.cabal
@@ -1,5 +1,5 @@
 name:          unbounded-delays
-version:       0.1.0.3
+version:       0.1.0.4
 cabal-version: >= 1.6
 build-type:    Custom
 author:        Bas van Dijk <v.dijk.bas@gmail.com>