diff --git a/components/vfs/vfs_cdcacm.c b/components/vfs/vfs_cdcacm.c
index fb590a445d..357e67277f 100644
--- a/components/vfs/vfs_cdcacm.c
+++ b/components/vfs/vfs_cdcacm.c
@@ -271,7 +271,7 @@ static int cdcacm_fcntl(int fd, int cmd, int arg)
     assert(fd == 0);
     int result;
     if (cmd == F_GETFL) {
-        result = 0;
+        result = O_RDWR;
         if (!s_blocking) {
             result |= O_NONBLOCK;
         }
diff --git a/components/vfs/vfs_uart.c b/components/vfs/vfs_uart.c
index 1f3e0df683..74c308f326 100644
--- a/components/vfs/vfs_uart.c
+++ b/components/vfs/vfs_uart.c
@@ -299,6 +299,7 @@ static int uart_fcntl(int fd, int cmd, int arg)
     assert(fd >=0 && fd < 3);
     int result = 0;
     if (cmd == F_GETFL) {
+        result |= O_RDWR;
         if (s_ctx[fd]->non_blocking) {
             result |= O_NONBLOCK;
         }
diff --git a/components/vfs/vfs_usb_serial_jtag.c b/components/vfs/vfs_usb_serial_jtag.c
index f5ab0b1f79..a0d0771c6c 100644
--- a/components/vfs/vfs_usb_serial_jtag.c
+++ b/components/vfs/vfs_usb_serial_jtag.c
@@ -245,6 +245,7 @@ static int usb_serial_jtag_fcntl(int fd, int cmd, int arg)
 {
     int result = 0;
     if (cmd == F_GETFL) {
+        result |= O_RDWR;
         if (s_ctx.non_blocking) {
             result |= O_NONBLOCK;
         }