diff --git a/drivers/infiniband/core/agent.h b/drivers/infiniband/core/agent.h
index c5f3cfec942adb8f246e4d46adb4565b84dcf6fa..86d72fab37b0d4cccff79885368e608abd1ebcec 100644
--- a/drivers/infiniband/core/agent.h
+++ b/drivers/infiniband/core/agent.h
@@ -39,6 +39,7 @@
 #ifndef __AGENT_H_
 #define __AGENT_H_
 
+#include <linux/err.h>
 #include <rdma/ib_mad.h>
 
 extern int ib_agent_port_open(struct ib_device *device, int port_num);