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:               0.1.5
+version:               0.1.6
 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
@@ -16,7 +16,6 @@
 
 import BasicPrelude
 import Control.Lens
-import Data.Bits
 import Data.Time
 import Data.Word
 import Data.RTCM3
@@ -48,16 +47,19 @@
 
 toL :: GpsL1Observation -> GpsL1ExtObservation -> CarrierPhase
 toL l1 l1e = CarrierPhase
-  { _carrierPhase_i = fromIntegral $ iint `shiftR` 8
-  , _carrierPhase_f = fromIntegral $ iint .&. 0xFF
+  { _carrierPhase_i = fromIntegral li
+  , _carrierPhase_f = fromIntegral lf
   } where
     p = 0.02 * fromIntegral (l1 ^. gpsL1Observation_pseudorange) +
         299792.458 * fromIntegral (l1e ^. gpsL1ExtObservation_ambiguity)
     lm :: Double
     lm = p + 0.0005 * fromIntegral (l1 ^. gpsL1Observation_carrierMinusCode)
-    l = (lm - 22e6) / 0.190293673
-    iint :: Int64
-    iint = - round (l * 255.0)
+    l = -lm / (299792458.0 / 1.57542e9)
+    li :: Int32
+    li = floor (l)
+    lf :: Word8
+    lf = truncate ((l - fromIntegral li) * 256)
+
 
 toCn0 :: GpsL1ExtObservation -> Word8
 toCn0 = (^. gpsL1ExtObservation_cnr)