diff --git a/chardev/char-fd.c b/chardev/char-fd.c
index 6ec9682b22..cf78454841 100644
--- a/chardev/char-fd.c
+++ b/chardev/char-fd.c
@@ -212,8 +212,8 @@ void qemu_chr_open_fd(Chardev *chr,
     FDChardev *s = FD_CHARDEV(chr);
     g_autofree char *name = NULL;
 
-    if (fd_out >= 0) {
-        qemu_set_nonblock(fd_out);
+    if (fd_out >= 0 && !g_unix_set_fd_nonblocking(fd_out, true, NULL)) {
+        assert(!"Failed to set FD nonblocking");
     }
 
     if (fd_out == fd_in && fd_in >= 0) {
diff --git a/chardev/char-pty.c b/chardev/char-pty.c
index 1e2863f532..53f25c6bbd 100644
--- a/chardev/char-pty.c
+++ b/chardev/char-pty.c
@@ -324,7 +324,10 @@ static void char_pty_open(Chardev *chr,
     }
 
     close(slave_fd);
-    qemu_set_nonblock(master_fd);
+    if (!g_unix_set_fd_nonblocking(master_fd, true, NULL)) {
+        error_setg_errno(errp, errno, "Failed to set FD nonblocking");
+        return;
+    }
 
     chr->filename = g_strdup_printf("pty:%s", pty_name);
     qemu_printf("char device redirected to %s (label %s)\n",
diff --git a/chardev/char-serial.c b/chardev/char-serial.c
index 7c3d84ae24..4b0b83d5b4 100644
--- a/chardev/char-serial.c
+++ b/chardev/char-serial.c
@@ -271,7 +271,10 @@ static void qmp_chardev_open_serial(Chardev *chr,
     if (fd < 0) {
         return;
     }
-    qemu_set_nonblock(fd);
+    if (!g_unix_set_fd_nonblocking(fd, true, NULL)) {
+        error_setg_errno(errp, errno, "Failed to set FD nonblocking");
+        return;
+    }
     tty_serial_init(fd, 115200, 'N', 8, 1);
 
     qemu_chr_open_fd(chr, fd, fd);
diff --git a/chardev/char-stdio.c b/chardev/char-stdio.c
index 403da308c9..3c648678ab 100644
--- a/chardev/char-stdio.c
+++ b/chardev/char-stdio.c
@@ -103,7 +103,10 @@ static void qemu_chr_open_stdio(Chardev *chr,
     stdio_in_use = true;
     old_fd0_flags = fcntl(0, F_GETFL);
     tcgetattr(0, &oldtty);
-    qemu_set_nonblock(0);
+    if (!g_unix_set_fd_nonblocking(0, true, NULL)) {
+        error_setg_errno(errp, errno, "Failed to set FD nonblocking");
+        return;
+    }
     atexit(term_exit);
 
     memset(&act, 0, sizeof(act));