diff --git a/src/openvpn/multi.c b/src/openvpn/multi.c
index 3e72b92..c1ceb34 100644
--- a/src/openvpn/multi.c
+++ b/src/openvpn/multi.c
@@ -2833,7 +2833,7 @@
  * Add a mbuf buffer to a particular
  * instance.
  */
-void
+static void
 multi_add_mbuf(struct multi_context *m, struct multi_instance *mi, struct mbuf_buffer *mb)
 {
     if (multi_output_queue_ready(m, mi))
diff --git a/src/openvpn/multi.h b/src/openvpn/multi.h
index 6cb86c7..ac6cb78f 100644
--- a/src/openvpn/multi.h
+++ b/src/openvpn/multi.h
@@ -354,8 +354,6 @@
 
 struct multi_instance *multi_get_queue(struct mbuf_set *ms);
 
-void multi_add_mbuf(struct multi_context *m, struct multi_instance *mi, struct mbuf_buffer *mb);
-
 void multi_ifconfig_pool_persist(struct multi_context *m, bool force);
 
 bool multi_process_signal(struct multi_context *m);