diff --git a/Hledger/Interest.hs b/Hledger/Interest.hs
--- a/Hledger/Interest.hs
+++ b/Hledger/Interest.hs
@@ -51,7 +51,7 @@
   let posts = [ p | p <- tpostings ts, interestAcc == paccount p ]
   forM_ posts $ \p -> do
     bal <- gets (balance)
-    modify (\st -> st { balance = normaliseMixedAmount (bal + (pamount p)) })
+    modify (\st -> st { balance = normaliseMixedAmountPreservingFirstPrice (bal + (pamount p)) })
 
 computeInterest :: Day -> Computer ()
 computeInterest day = do
diff --git a/Main.hs b/Main.hs
--- a/Main.hs
+++ b/Main.hs
@@ -58,6 +58,7 @@
  , Option []    ["constant"]    (ReqArg (\r o -> o { optRate = Just (constant (read r)) }) "RATE")  "constant interest rate"
  , Option []    ["annual"]      (ReqArg (\r o -> o { optRate = Just (perAnno (read r)) }) "RATE")   "annual interest rate"
  , Option []    ["bgb288"]      (NoArg (\o -> o { optRate = Just bgb288, optDCC = Just diffAct }))  "compute interest according to German BGB288"
+ , Option []    ["ing-diba"]    (NoArg (\o -> o { optRate = Just ingDiba, optDCC = Just diffAct }))  "compute interest according for Ing-Diba Tagesgeld account"
  ]
 
 usageMessage :: String
diff --git a/hledger-interest.cabal b/hledger-interest.cabal
--- a/hledger-interest.cabal
+++ b/hledger-interest.cabal
@@ -1,5 +1,5 @@
 Name:                   hledger-interest
-Version:                1.3
+Version:                1.4
 Synopsis:               computes interest for a given account
 License:                BSD3
 License-file:           LICENSE
@@ -9,7 +9,7 @@
 Category:               Finance
 Build-type:             Simple
 Cabal-version:          >= 1.6
-Tested-with:            GHC == 6.12.3, GHC == 7.0.4, GHC == 7.2.1
+Tested-with:            GHC == 6.12.3, GHC == 7.0.4, GHC == 7.4.1
 Data-files:             README.md
 Description:
  hledger-interest is a small command-line utility based on Simon
@@ -112,7 +112,7 @@
 
 Executable hledger-interest
   Main-is:              Main.hs
-  Build-depends:        base >= 3 && < 5, hledger-lib >= 0.14, time, mtl, Cabal
+  Build-depends:        base >= 3 && < 5, hledger-lib >= 0.17, time, mtl, Cabal
   other-modules:        Hledger.Interest
                         Hledger.Interest.DayCountConvention
                         Hledger.Interest.Rate