diff --git a/lib/rational.c b/lib/rational.c
index b3c099b..3ed247b 100644
--- a/lib/rational.c
+++ b/lib/rational.c
@@ -7,6 +7,7 @@
  */
 
 #include <linux/rational.h>
+#include <linux/module.h>
 
 /*
  * calculate best rational approximation for a given fraction