diff --git a/DCC.cpp b/DCC.cpp
index a4e1fcc..f8d37ea 100644
--- a/DCC.cpp
+++ b/DCC.cpp
@@ -683,9 +683,9 @@ ackOp  const *  DCC::ackManagerProgStart;
 byte   DCC::ackManagerByte;
 byte   DCC::ackManagerStash;
 int    DCC::ackManagerWord;
-int    DCC::ackManagerRetry;
-int    DCC::ackRetry = 2;
-int    DCC::ackRetrySum;
+byte   DCC::ackManagerRetry;
+byte   DCC::ackRetry = 2;
+int16_t  DCC::ackRetrySum;
 int    DCC::ackManagerCv;
 byte   DCC::ackManagerBitNum;
 bool   DCC::ackReceived;