diff --git a/src/Lib.hs b/src/Lib.hs
index 2858cc9cee86e39989951396f6f2f836848bfa4d..3bb7a13b5e6f1f32e2bad739978e4b034757b5e9 100755
--- a/src/Lib.hs
+++ b/src/Lib.hs
@@ -10,7 +10,7 @@ import GHC.Generics
 import Data.Aeson
 import Aws.Lambda
 import qualified Data.ByteString.Lazy.Char8 as ByteString
-import qualified InterestRateReturn
+import qualified NetPresentValue
 
 -- Input
 data Event = Event
@@ -30,11 +30,11 @@ header = object ["Access-Control-Allow-Origin" .= ("*" :: String)]
 handler :: Event -> Context () -> IO (Either String Response)
 handler Event{..} context = do
   case decode (ByteString.pack body) of
-    Just inputInterestRateReturn ->
+    Just inputNetPresentValue ->
       pure $ Right Response
         { statusCode = 200
         , headers = header
-        , body = InterestRateReturn.calculateInterestRateReturn inputInterestRateReturn
+        , body = NetPresentValue.calculateNetPresentValue inputNetPresentValue
         }
     Nothing ->
       pure $ Right Response
diff --git a/src/InterestRateReturn.hs b/src/NetPresentValue.hs
similarity index 52%
rename from src/InterestRateReturn.hs
rename to src/NetPresentValue.hs
index a38718514466f28ed6d350060290d03080de84c7..f3bb4d5a245598bc3aa6dce85de7333058f45581 100644
--- a/src/InterestRateReturn.hs
+++ b/src/NetPresentValue.hs
@@ -4,19 +4,19 @@
 {-# LANGUAGE DeriveGeneric #-}
 {-# LANGUAGE OverloadedStrings #-}
 
-module InterestRateReturn where
+module NetPresentValue where
 
 import GHC.Generics
 import Aws.Lambda
 import Data.Aeson
 
-data InputInterestRateReturn = InputInterestRateReturn
+data InputNetPresentValue = InputNetPresentValue
     { income_1 :: Int
     , outcome_1 :: Int
     } deriving (Generic, FromJSON, ToJSON)
 
-calculateInterestRateReturn :: InputInterestRateReturn -> Int
-calculateInterestRateReturn inputInterestRateReturn = p + q
+calculateNetPresentValue :: InputNetPresentValue -> Int
+calculateNetPresentValue inputNetPresentValue = p + q
     where
-        p = income_1 inputInterestRateReturn
-        q = outcome_1 inputInterestRateReturn   
\ No newline at end of file
+        p = income_1 inputNetPresentValue
+        q = outcome_1 inputNetPresentValue   
\ No newline at end of file