diff --git a/client/cmdhf14a.c b/client/cmdhf14a.c
index 330fbec0..b369d187 100644
--- a/client/cmdhf14a.c
+++ b/client/cmdhf14a.c
@@ -731,7 +731,7 @@ int CmdHF14ACmdRaw(const char *cmd) {
 		
 		// Max buffer is USB_CMD_DATA_SIZE
 		datalen	=  (datalen > USB_CMD_DATA_SIZE) ? USB_CMD_DATA_SIZE : datalen;
-    c.arg[1] = (datalen & 0xFFFF) | (numbits << 16);
+    c.arg[1] = (datalen & 0xFFFF) | ( (uint32_t)(numbits) << 16);
     memcpy(c.d.asBytes,data,datalen);
 
     SendCommand(&c);