diff --git a/src/content_mapblock.cpp b/src/content_mapblock.cpp
index 68895c396..ff8ef5276 100644
--- a/src/content_mapblock.cpp
+++ b/src/content_mapblock.cpp
@@ -26,6 +26,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "tile.h"
 #include "gamedef.h"
 #include "util/numeric.h"
+#include "util/serialize.h"
 #include "util/directiontables.h"
 
 // Create a cuboid.