diff --git a/arch/um/os-Linux/file.c b/arch/um/os-Linux/file.c
index b5afcfd..140e587 100644
--- a/arch/um/os-Linux/file.c
+++ b/arch/um/os-Linux/file.c
@@ -561,3 +561,18 @@
  out:
 	return err;
 }
+
+unsigned os_major(unsigned long long dev)
+{
+	return major(dev);
+}
+
+unsigned os_minor(unsigned long long dev)
+{
+	return minor(dev);
+}
+
+unsigned long long os_makedev(unsigned major, unsigned minor)
+{
+	return makedev(major, minor);
+}