diff --git a/src/epoll-socket.c b/src/epoll-socket.c
index f493665..cbdef0a 100644
--- a/src/epoll-socket.c
+++ b/src/epoll-socket.c
@@ -57,7 +57,7 @@ ep_sock_t* ep_sock_new(_ep_port_data_t* port_data) {
   if (sock_private == NULL)
     return NULL;
 
-  (void) port_data;
+  unused(port_data);
 
   memset(sock_private, 0, sizeof *sock_private);
   handle_tree_entry_init(&sock_private->pub.tree_entry);
diff --git a/src/util.h b/src/util.h
index 20c1984..b2e76b2 100644
--- a/src/util.h
+++ b/src/util.h
@@ -13,4 +13,6 @@ typedef intptr_t ssize_t;
 #define container_of(ptr, type, member) \
   ((type*) ((char*) (ptr) -offsetof(type, member)))
 
+#define unused(v) ((void) (v))
+
 #endif /* EPOLL_UTIL_H_ */