diff --git a/alarmclock.cabal b/alarmclock.cabal
--- a/alarmclock.cabal
+++ b/alarmclock.cabal
@@ -1,5 +1,5 @@
 name:                alarmclock
-version:             0.4.0.3
+version:             0.4.0.4
 synopsis:            Wake up and perform an action at a certain time.
 description:         Wake up and perform an action at a certain time.
 homepage:            https://bitbucket.org/davecturner/alarmclock
@@ -15,7 +15,7 @@
 library
   exposed-modules:     Control.Concurrent.AlarmClock
   build-depends:
-      base >=4.8 && <4.11
+      base >=4.8 && <4.12
     , stm
     , async
     , time
diff --git a/src/Control/Concurrent/AlarmClock.hs b/src/Control/Concurrent/AlarmClock.hs
--- a/src/Control/Concurrent/AlarmClock.hs
+++ b/src/Control/Concurrent/AlarmClock.hs
@@ -47,7 +47,7 @@
 import           GHC.Conc                   (labelThread, myThreadId)
 import           System.Clock               (Clock (Monotonic), TimeSpec,
                                              diffTimeSpec, getTime,
-                                             timeSpecAsNanoSecs)
+                                             toNanoSecs)
 
 class TimeScale t where
   getAbsoluteTime   :: IO t
@@ -66,7 +66,7 @@
   getAbsoluteTime = MonotonicTime <$> getTime Monotonic
   earlierOf       = min
   microsecondsDiff (MonotonicTime t1) (MonotonicTime t2)
-                  = (`div` 1000) $ timeSpecAsNanoSecs $ diffTimeSpec t1 t2
+                  = (`div` 1000) $ toNanoSecs $ diffTimeSpec t1 t2
 
 {-| An 'AlarmClock' is a device for running an action at (or shortly after) a certain time. -}
 data AlarmClock t = AlarmClock