diff --git a/src/layout/arrange.h b/src/layout/arrange.h
index 3b8dbf31..533cfc41 100644
--- a/src/layout/arrange.h
+++ b/src/layout/arrange.h
@@ -1,3 +1,5 @@
+#include <assert.h>
+
 void save_old_size_per(Monitor *m) {
 	Client *c = NULL;
 
diff --git a/src/mango.c b/src/mango.c
index 961358bf..6369bed0 100644
--- a/src/mango.c
+++ b/src/mango.c
@@ -1111,15 +1111,15 @@ static struct wl_event_source *sync_keymap;
 #include "animation/tag.h"
 static void canvas_reposition(Monitor *m);
 static void canvas_pan_to_client(Monitor *m, Client *c);
-#include "dispatch/bind_define.h"
-#include "dispatch/gesture.h"
-#include "ext-protocol/all.h"
-#include "fetch/fetch.h"
 #include "layout/arrange.h"
 #include "layout/canvas.h"
 #include "layout/dwindle.h"
 #include "layout/horizontal.h"
 #include "layout/vertical.h"
+#include "dispatch/bind_define.h"
+#include "dispatch/gesture.h"
+#include "ext-protocol/all.h"
+#include "fetch/fetch.h"
 
 void client_change_mon(Client *c, Monitor *m) {
 	setmon(c, m, c->tags, true);