diff --git a/main/biome.h b/main/biome.h
index 02633a9..1b527a7 100644
--- a/main/biome.h
+++ b/main/biome.h
@@ -44,8 +44,8 @@ SOFTWARE.
 
 class BiomeData;
 
-class Biome : public Reference {
-	GDCLASS(Biome, Reference);
+class Biome : public Resource {
+	GDCLASS(Biome, Resource);
 
 public:
 	int get_current_seed();
diff --git a/main/dungeon.h b/main/dungeon.h
index 3e7c199..d4ba82b 100644
--- a/main/dungeon.h
+++ b/main/dungeon.h
@@ -24,6 +24,7 @@ SOFTWARE.
 #define DUNGEON_H
 
 #include "core/reference.h"
+#include "core/resource.h"
 
 #include "dungeon_corridor.h"
 #include "dungeon_room.h"
@@ -45,8 +46,8 @@ SOFTWARE.
 
 class DungeonData;
 
-class Dungeon : public Reference {
-	GDCLASS(Dungeon, Reference);
+class Dungeon : public Resource {
+	GDCLASS(Dungeon, Resource);
 
 public:
 	int get_current_seed();
diff --git a/main/dungeon_room.h b/main/dungeon_room.h
index d3df260..2f1e927 100644
--- a/main/dungeon_room.h
+++ b/main/dungeon_room.h
@@ -24,6 +24,7 @@ SOFTWARE.
 #define DUNGEON_ROOM_H
 
 #include "core/reference.h"
+#include "core/resource.h"
 #include "core/vector.h"
 
 #include "../data/dungeon_room_data.h"
@@ -46,8 +47,8 @@ SOFTWARE.
 
 class DungeonRoomData;
 
-class DungeonRoom : public Reference {
-	GDCLASS(DungeonRoom, Reference);
+class DungeonRoom : public Resource {
+	GDCLASS(DungeonRoom, Resource);
 
 public:
 	int get_current_seed();
diff --git a/main/planet.h b/main/planet.h
index 84ab262..9706a7e 100644
--- a/main/planet.h
+++ b/main/planet.h
@@ -25,6 +25,7 @@ SOFTWARE.
 
 #include "core/image.h"
 #include "core/reference.h"
+#include "core/resource.h"
 
 #include "biome.h"
 #include "dungeon.h"
@@ -40,8 +41,8 @@ SOFTWARE.
 
 class PlanetData;
 
-class Planet : public Reference {
-	GDCLASS(Planet, Reference);
+class Planet : public Resource {
+	GDCLASS(Planet, Resource);
 
 public:
 	int get_current_seed();