diff --git a/drafts/GameEngine.draft.h b/drafts/GameEngine.draft.hpp
similarity index 73%
rename from drafts/GameEngine.draft.h
rename to drafts/GameEngine.draft.hpp
index 839c8d1..3b95fd1 100644
--- a/drafts/GameEngine.draft.h
+++ b/drafts/GameEngine.draft.hpp
@@ -11,12 +11,12 @@
 #ifndef LGEN_MODULE_GAMEENGINE_DRAFT
 #define LGEN_MODULE_GAMEENGINE_DRAFT 1
 
-#include "coord.h"  // lib coord
+#include "coord.hpp"  // lib coord
 
-#include "player.h"  // players
+#include "player.hpp"  // players
 
-#include "tile.h"  // tiles
+#include "tile.hpp"  // tiles
 
-#include "board.h"  // boards
+#include "board.hpp"  // boards
 
 #endif  // LGEN_MODULE_GAMEENGINE_DRAFT
diff --git a/drafts/board.h b/drafts/board.hpp
similarity index 97%
rename from drafts/board.h
rename to drafts/board.hpp
index f88e8b8..66e9b16 100644
--- a/drafts/board.h
+++ b/drafts/board.hpp
@@ -11,10 +11,10 @@
 #include <cassert>
 #include <vector>
 
-#include "coord.h"
+#include "coord.hpp"
 
-#include "player.h"
-#include "tile.h"
+#include "player.hpp"
+#include "tile.hpp"
 
 /// Game map board. Zoomable.
 /// The %Board is a complex thing. Many systems are part of it (e.g. vision system).
diff --git a/drafts/coord.h b/drafts/coord.hpp
similarity index 100%
rename from drafts/coord.h
rename to drafts/coord.hpp
diff --git a/drafts/player.h b/drafts/player.hpp
similarity index 96%
rename from drafts/player.h
rename to drafts/player.hpp
index 0dfbd57..aeeecf7 100644
--- a/drafts/player.h
+++ b/drafts/player.hpp
@@ -12,7 +12,6 @@
 #define LGEN_MODULE_GE_PLAYER 1
 
 #include <string>
-#include "board.h"
 
 /// Base struct for players.
 class Player {
diff --git a/drafts/tile.h b/drafts/tile.hpp
similarity index 99%
rename from drafts/tile.h
rename to drafts/tile.hpp
index 55de2da..2dfdfc3 100644
--- a/drafts/tile.h
+++ b/drafts/tile.hpp
@@ -13,7 +13,7 @@
 
 #include <cstdint>
 
-#include "player.h"
+#include "player.hpp"
 
 using army_t = int64_t;