diff --git a/gnss-converters.cabal b/gnss-converters.cabal
--- a/gnss-converters.cabal
+++ b/gnss-converters.cabal
@@ -1,5 +1,5 @@
 name:                  gnss-converters
-version:               0.1.17
+version:               0.1.18
 synopsis:              GNSS Converters.
 description:           Haskell bindings for GNSS converters.
 homepage:              http://github.com/swift-nav/gnss-converters
diff --git a/src/Data/RTCM3/SBP.hs b/src/Data/RTCM3/SBP.hs
--- a/src/Data/RTCM3/SBP.hs
+++ b/src/Data/RTCM3/SBP.hs
@@ -18,7 +18,7 @@
   , q32Width
   , toWn
   , mjdEpoch
-  , updateGPSTime
+  , updateGpsTime
   , updateLock
   , convert
   , newStore
@@ -173,31 +173,31 @@
 fromEcefVal :: Int64 -> Double
 fromEcefVal x = fromIntegral x / 10000
 
-newGPSTime :: MonadStore e m => Word32 -> m ObsGPSTime
-newGPSTime tow = do
+newGpsTime :: MonadStore e m => Word32 -> m GpsTime
+newGpsTime tow = do
   wn <- view storeWn >>= liftIO . readIORef
-  return ObsGPSTime
-    { _obsGPSTime_tow = tow
-    , _obsGPSTime_wn  = wn
+  return GpsTime
+    { _gpsTime_tow = tow
+    , _gpsTime_wn  = wn
     }
 
 -- | If incoming TOW is less than stored TOW, rollover WN.
 --
-updateGPSTime :: Word32 -> ObsGPSTime -> ObsGPSTime
-updateGPSTime tow gpsTime =
-  gpsTime & obsGPSTime_tow .~ tow &
-    if tow >= gpsTime ^. obsGPSTime_tow then id else
-      obsGPSTime_wn %~ (+ 1)
+updateGpsTime :: Word32 -> GpsTime -> GpsTime
+updateGpsTime tow gpsTime =
+  gpsTime & gpsTime_tow .~ tow &
+    if tow >= gpsTime ^. gpsTime_tow then id else
+      gpsTime_wn %~ (+ 1)
 
 -- | Produce GPS Time from Observation header, handling WN rollover.
 --
-toGPSTime :: MonadStore e m => GpsObservationHeader -> m ObsGPSTime
-toGPSTime hdr = do
+toGpsTime :: MonadStore e m => GpsObservationHeader -> m GpsTime
+toGpsTime hdr = do
   let tow      = hdr ^. gpsObservationHeader_tow
       station  = hdr ^. gpsObservationHeader_station
-  gpsTime      <- newGPSTime tow
-  gpsTimeMap   <- view storeGPSTimeMap
-  liftIO $ modifyMap gpsTimeMap gpsTime station $ updateGPSTime tow
+  gpsTime      <- newGpsTime tow
+  gpsTimeMap   <- view storeGpsTimeMap
+  liftIO $ modifyMap gpsTimeMap gpsTime station $ updateGpsTime tow
 
 -- | MJD GPS Epoch - First day in GPS week 0. See DF051 of the RTCM3 spec
 --
@@ -329,7 +329,7 @@
                          -> GpsObservationHeader -- ^ RTCM observation header
                          -> m ObservationHeader
 fromGpsObservationHeader totalMsgs n hdr = do
-  t <- toGPSTime hdr
+  t <- toGpsTime hdr
   return ObservationHeader
     { _observationHeader_t     = t
     -- First nibble is the size of the sequence (n), second nibble is the
diff --git a/src/Data/RTCM3/SBP/Types.hs b/src/Data/RTCM3/SBP/Types.hs
--- a/src/Data/RTCM3/SBP/Types.hs
+++ b/src/Data/RTCM3/SBP/Types.hs
@@ -37,7 +37,7 @@
 
 $(makeLenses ''Lock)
 
-type GPSTimeMap = HashMap Word16 ObsGPSTime
+type GpsTimeMap = HashMap Word16 GpsTime
 type LockMap    = HashMap (Word16, GnssSignal) Lock
 
 instance Hashable GnssSignal where
@@ -75,7 +75,7 @@
 data Store = Store
   { _storeWn         :: IORef Word16
   , _storeLockMap    :: IORef LockMap
-  , _storeGPSTimeMap :: IORef GPSTimeMap
+  , _storeGpsTimeMap :: IORef GpsTimeMap
   } deriving ( Eq )
 
 $(makeClassy ''Store)
diff --git a/test/Test/Data/RTCM3/SBP.hs b/test/Test/Data/RTCM3/SBP.hs
--- a/test/Test/Data/RTCM3/SBP.hs
+++ b/test/Test/Data/RTCM3/SBP.hs
@@ -156,39 +156,39 @@
         assertExpectedBase (msgs !! 5) expectedBasePos
         -- Message 1
         assertObsHeader (msgs !! 1) ObservationHeader {
-            _observationHeader_t     = ObsGPSTime 86354000 1906
+            _observationHeader_t     = GpsTime 86354000 1906
           , _observationHeader_n_obs = 32
           }
         assertMsgObsLength (msgs !! 1) 15
         assertMsgObs (msgs !! 1)
         -- Message 2
         assertObsHeader (msgs !! 2) ObservationHeader {
-            _observationHeader_t     = ObsGPSTime 86354000 1906
+            _observationHeader_t     = GpsTime 86354000 1906
           , _observationHeader_n_obs = 33
           }
         assertMsgObs (msgs !! 2)
         assertMsgObsLength (msgs !! 2) 1
         -- Message 3
         assertObsHeader (msgs !! 3) ObservationHeader {
-            _observationHeader_t     = ObsGPSTime 86355000 1906
+            _observationHeader_t     = GpsTime 86355000 1906
           , _observationHeader_n_obs = 32
           }
         assertMsgObsLength (msgs !! 3) 15
         -- Message 4
         assertObsHeader (msgs !! 4) ObservationHeader {
-            _observationHeader_t     = ObsGPSTime 86355000 1906
+            _observationHeader_t     = GpsTime 86355000 1906
           , _observationHeader_n_obs = 33
           }
         assertMsgObsLength (msgs !! 4) 1
         -- Message 6
         assertObsHeader (msgs !! 6) ObservationHeader {
-            _observationHeader_t     = ObsGPSTime 86356000 1906
+            _observationHeader_t     = GpsTime 86356000 1906
           , _observationHeader_n_obs = 32
           }
         assertMsgObsLength (msgs !! 6) 15
         -- Message 7
         assertObsHeader (msgs !! 7) ObservationHeader {
-            _observationHeader_t     = ObsGPSTime 86356000 1906
+            _observationHeader_t     = GpsTime 86356000 1906
           , _observationHeader_n_obs = 33
           }
         assertMsgObsLength (msgs !! 7) 1
@@ -211,21 +211,21 @@
        toWn 57593 @?= 1907
     ]
 
-testUpdateGPSTime :: TestTree
-testUpdateGPSTime =
+testUpdateGpsTime :: TestTree
+testUpdateGpsTime =
   testGroup "Update GPS Time"
     [ testCase "old TOW < new TOW" $ do
-        let old = ObsGPSTime 1 10
-            new = updateGPSTime 2 old
-        new ^. obsGPSTime_wn @?= 10
+        let old = GpsTime 1 10
+            new = updateGpsTime 2 old
+        new ^. gpsTime_wn @?= 10
     , testCase "old TOW = new TOW" $ do
-        let old = ObsGPSTime 1 10
-            new = updateGPSTime 1 old
-        new ^. obsGPSTime_wn @?= 10
+        let old = GpsTime 1 10
+            new = updateGpsTime 1 old
+        new ^. gpsTime_wn @?= 10
     , testCase "old TOW > new TOW" $ do
-        let old = ObsGPSTime 1 10
-            new = updateGPSTime 0 old
-        new ^. obsGPSTime_wn @?= 11
+        let old = GpsTime 1 10
+            new = updateGpsTime 0 old
+        new ^. gpsTime_wn @?= 11
     ]
 
 testUpdateLock :: TestTree
@@ -250,6 +250,6 @@
   testGroup "RTCM3 to SBP conversion tests"
     [ testMsg1004
     , testToWn
-    , testUpdateGPSTime
+    , testUpdateGpsTime
     , testUpdateLock
     ]