diff --git a/udev.h b/udev.h
index 08188ea..91b520b 100644
--- a/udev.h
+++ b/udev.h
@@ -1,6 +1,9 @@
 #include <sys/types.h>
 #include <sys/sysmacros.h>
 
+#ifndef _LIBUDEV_H_
+#define _LIBUDEV_H_
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -102,3 +105,5 @@ struct udev_device *udev_device_new_from_file(struct udev *udev, const char *pat
 #ifdef __cplusplus
 }
 #endif
+
+#endif