diff --git a/src/signs_base.h b/src/signs_base.h
--- a/src/signs_base.h
+++ b/src/signs_base.h
@@ -8,7 +8,7 @@
 #include "signs_type.h"
 #include "viewport_type.h"
 #include "tile_type.h"
-#include "core/pool.hpp"
+#include "core/pool_type.hpp"
 
 typedef Pool<Sign, SignID, 16, 64000> SignPool;
 extern SignPool _sign_pool;