diff --git a/AfRApay.FTM/Program.cs b/AfRApay.FTM/Program.cs
index 13b2fd6..f02e866 100644
--- a/AfRApay.FTM/Program.cs
+++ b/AfRApay.FTM/Program.cs
@@ -148,7 +148,7 @@ static async void HandleTap(IIsoReader reader, HttpClient httpClient, TerminalSt
     switch (state) {
         case TerminalState.Debit:
         case TerminalState.Credit:
-            var finalAmount = Math.Abs(amount) * (state == TerminalState.Debit ? 1 : -1);
+            var finalAmount = Math.Abs(amount) * (state == TerminalState.Debit ? -1 : 1);
             var idempotencyKey = new byte[18];
             Random.Shared.NextBytes(idempotencyKey);
             var ik = Convert.ToHexString(idempotencyKey);