diff --git a/lib/assoc_array.c b/lib/assoc_array.c
index 2404d03..03dd576 100644
--- a/lib/assoc_array.c
+++ b/lib/assoc_array.c
@@ -11,6 +11,7 @@
  * 2 of the Licence, or (at your option) any later version.
  */
 //#define DEBUG
+#include <linux/rcupdate.h>
 #include <linux/slab.h>
 #include <linux/err.h>
 #include <linux/assoc_array_priv.h>