diff --git a/arguments.c b/arguments.c
index 05ff97eb..54753de3 100644
--- a/arguments.c
+++ b/arguments.c
@@ -29,6 +29,12 @@
  * Manipulate command arguments.
  */
 
+struct args_entry {
+	u_char			 flag;
+	char			*value;
+	RB_ENTRY(args_entry)	 entry;
+};
+
 struct args_entry	*args_find(struct args *, u_char);
 
 RB_GENERATE(args_tree, args_entry, entry, args_cmp);
diff --git a/tmux.h b/tmux.h
index 822bdc93..6b462589 100644
--- a/tmux.h
+++ b/tmux.h
@@ -1257,13 +1257,8 @@ struct client {
 TAILQ_HEAD(clients, client);
 
 /* Parsed arguments structures. */
-struct args_entry {
-	u_char			 flag;
-	char			*value;
-	RB_ENTRY(args_entry)	 entry;
-};
+struct args_entry;
 RB_HEAD(args_tree, args_entry);
-
 struct args {
 	struct args_tree	  tree;
 	int			  argc;