diff --git a/include/linux/greybus/operation.h b/include/linux/greybus/operation.h
index 8ca864bba23e..cb8e4ef45222 100644
--- a/include/linux/greybus/operation.h
+++ b/include/linux/greybus/operation.h
@@ -15,7 +15,7 @@
 #include <linux/types.h>
 #include <linux/workqueue.h>
 
-
+struct gb_host_device;
 struct gb_operation;
 
 /* The default amount of time a request is given to complete */
diff --git a/include/linux/greybus/svc.h b/include/linux/greybus/svc.h
index 507f8bd4e4c8..5afaf5f06856 100644
--- a/include/linux/greybus/svc.h
+++ b/include/linux/greybus/svc.h
@@ -12,6 +12,8 @@
 #include <linux/types.h>
 #include <linux/device.h>
 
+struct gb_svc_l2_timer_cfg;
+
 #define GB_SVC_CPORT_FLAG_E2EFC		BIT(0)
 #define GB_SVC_CPORT_FLAG_CSD_N		BIT(1)
 #define GB_SVC_CPORT_FLAG_CSV_N		BIT(2)