diff --git a/src/RS232_win.c b/src/RS232_win.c
--- a/src/RS232_win.c
+++ b/src/RS232_win.c
@@ -204,7 +204,7 @@ int rs232setup(rs232port_t fd, int ChSiz
                 dcbSerialParams.Parity=privatedecodeparity(Parity);
                 SetCommState((HANDLE)fd, &dcbSerialParams);
                 COMMTIMEOUTS timeouts={0};
-                timeouts.ReadIntervalTimeout=100;
+                timeouts.ReadIntervalTimeout=5;
                 timeouts.ReadTotalTimeoutConstant=100;
                 timeouts.ReadTotalTimeoutMultiplier=1;
                 timeouts.WriteTotalTimeoutConstant=100;