diff --git a/system/zmodem/README.txt b/system/zmodem/README.txt
index 620dfa998..25e0f4a68 100755
--- a/system/zmodem/README.txt
+++ b/system/zmodem/README.txt
@@ -127,6 +127,7 @@ Using NuttX Zmodem with a Linux Host
 
       $ sudo stty -F /dev/ttyS0 9600     # Select 9600 (or other) BAUD
       $ sudo stty -F /dev/ttyS0 crtscts  # Enables CTS/RTS handshaking *
+      $ sudo stty -F /dev/ttyS0 raw      # Puts the TTY in raw mode
       $ sudo stty -F /dev/ttyS0          # Show the TTY configuration
 
      * Only is hardware flow control is enabled.
diff --git a/system/zmodem/rz_main.c b/system/zmodem/rz_main.c
index 08f73dbc8..38b889eaf 100644
--- a/system/zmodem/rz_main.c
+++ b/system/zmodem/rz_main.c
@@ -45,11 +45,13 @@
 #include <string.h>
 #include <signal.h>
 #include <fcntl.h>
+#include <termios.h>
 #include <libgen.h>
 #include <time.h>
 #include <errno.h>
 
 #include "system/zmodem.h"
+#include "zm.h"
 
 /****************************************************************************
  * Private Functions
@@ -155,8 +157,16 @@ int rz_main(int argc, FAR char **argv)
 
 errout_with_zmodem:
   (void)zmr_release(handle);
+
 errout_with_device:
+#ifdef CONFIG_SYSTEM_ZMODEM_FLOWC
+  /* Flush the serial output to assure do not hang trying to drain it */
+
+  tcflush(fd, TCIOFLUSH);
+#endif
+
   (void)close(fd);
+
 errout:
   return exitcode;
 }
diff --git a/system/zmodem/sz_main.c b/system/zmodem/sz_main.c
index 1413e9c66..5bcc8e046 100644
--- a/system/zmodem/sz_main.c
+++ b/system/zmodem/sz_main.c
@@ -45,11 +45,13 @@
 #include <string.h>
 #include <signal.h>
 #include <fcntl.h>
+#include <termios.h>
 #include <libgen.h>
 #include <time.h>
 #include <errno.h>
 
 #include "system/zmodem.h"
+#include "zm.h"
 
 /****************************************************************************
  * Private Functions
@@ -261,8 +263,16 @@ int sz_main(int argc, FAR char **argv)
 
 errout_with_zmodem:
   (void)zms_release(handle);
+
 errout_with_device:
+#ifdef CONFIG_SYSTEM_ZMODEM_FLOWC
+  /* Flush the serial output to assure do not hang trying to drain it */
+
+  tcflush(fd, TCIOFLUSH);
+#endif
+
   (void)close(fd);
+
 errout:
   return exitcode;
 }