diff --git a/src/system/kernel/fs/fd.cpp b/src/system/kernel/fs/fd.cpp
index 45de3762ad..cc9d7f7fb4 100644
--- a/src/system/kernel/fs/fd.cpp
+++ b/src/system/kernel/fs/fd.cpp
@@ -919,11 +919,12 @@ _user_seek(int fd, off_t pos, int seekType)
 status_t
 _user_ioctl(int fd, uint32 op, void* buffer, size_t length)
 {
-	if (buffer != NULL && !IS_USER_ADDRESS(buffer))
-		return B_BAD_ADDRESS;
-
 	TRACE(("user_ioctl: fd %d\n", fd));
 
+	// "buffer" is not always a pointer depending on "op", so we cannot
+	// check that it is a userland buffer here; the underlying implementation
+	// must do that.
+
 	SyscallRestartWrapper<status_t> status;
 
 	return status = fd_ioctl(false, fd, op, buffer, length);
diff --git a/src/tests/system/libroot/posix/termios.cpp b/src/tests/system/libroot/posix/termios.cpp
new file mode 100644
index 0000000000..31bbed525e
--- /dev/null
+++ b/src/tests/system/libroot/posix/termios.cpp
@@ -0,0 +1,60 @@
+/*
+ * Copyright 2019, Jérôme Duval, jerome.duval@gmail.com.
+ * Distributed under the terms of the MIT License.
+ */
+
+
+#include <ctype.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <termios.h>
+#include <unistd.h>
+
+
+extern const char *__progname;
+
+
+int
+main(int argc, char **argv)
+{
+	if (argc < 2) {
+		fprintf(stderr, "usage: %s <file>\n", __progname);
+		return 1;
+	}
+
+	int fd = open(argv[1], O_RDONLY);
+	if (fd < 0) {
+		fprintf(stderr, "%s: could open the file read-only \"%s\": %s\n",
+			__progname, argv[1], strerror(errno));
+		return 1;
+	}
+	int err = tcdrain(fd);
+	if (err != -1 || errno != ENOTTY) {
+		fprintf(stderr, "%s: tcdrain didn't fail with ENOTTY \"%s\": %s\n",
+			__progname, argv[1], strerror(errno));
+		close(fd);
+		return 1;
+	}
+	err = tcflow(fd, TCION);
+	if (err != -1 || errno != ENOTTY) {
+		fprintf(stderr, "%s: tcflow didn't fail with ENOTTY \"%s\": %s\n",
+			__progname, argv[1], strerror(errno));
+		close(fd);
+		return 1;
+	}
+
+	err = tcflush(fd, TCIOFLUSH);
+	if (err != -1 || errno != ENOTTY) {
+		fprintf(stderr, "%s: tcflush didn't fail with ENOTTY \"%s\": %s\n",
+			__progname, argv[1], strerror(errno));
+		close(fd);
+		return 1;
+	}
+
+	close(fd);
+
+	return 0;
+}