diff --git a/include/linux/timeriomem-rng.h b/include/linux/timeriomem-rng.h
index fd4a6e6ec831..672df7fbf6c1 100644
--- a/include/linux/timeriomem-rng.h
+++ b/include/linux/timeriomem-rng.h
@@ -5,6 +5,9 @@
  * Copyright (c) 2009 Alexander Clouter <alex@digriz.org.uk>
  */
 
+#ifndef _LINUX_TIMERIOMEM_RNG_H
+#define _LINUX_TIMERIOMEM_RNG_H
+
 struct timeriomem_rng_data {
 	void __iomem		*address;
 
@@ -14,3 +17,5 @@ struct timeriomem_rng_data {
 	/* bits of entropy per 1024 bits read */
 	unsigned int		quality;
 };
+
+#endif /* _LINUX_TIMERIOMEM_RNG_H */