diff --git a/cmdmon.c b/cmdmon.c
index e3ec9e0..b056770 100644
--- a/cmdmon.c
+++ b/cmdmon.c
@@ -1378,8 +1378,8 @@ handle_doffset(CMD_Request *rx_message, CMD_Reply *tx_message)
 {
   long sec, usec;
   double doffset;
-  sec = (long)(ntohl(rx_message->data.doffset.sec));
-  usec = (long)(ntohl(rx_message->data.doffset.usec));
+  sec = (int32_t)ntohl(rx_message->data.doffset.sec);
+  usec = (int32_t)ntohl(rx_message->data.doffset.usec);
   doffset = (double) sec + 1.0e-6 * (double) usec;
   LOG(LOGS_INFO, LOGF_CmdMon, "Accumulated delta offset of %.6f seconds", doffset);
   LCL_AccumulateOffset(doffset, 0.0);