diff --git a/site_ansto/hardsup/sct_lfprot.c b/site_ansto/hardsup/sct_lfprot.c
index 962fb878..7ed7f734 100644
--- a/site_ansto/hardsup/sct_lfprot.c
+++ b/site_ansto/hardsup/sct_lfprot.c
@@ -67,8 +67,8 @@ BYTE getHexCode(BYTE startPos, char *str){
 */
 int LFGenWriteStart(Ascon *a) {
 
-  char         *pNewBuffer;
-  unsigned char bufSize, bufInd;
+  char          *pNewBuffer;
+  unsigned short bufSize, bufInd;
 
   double now;