diff --git a/economy.c b/economy.c
index 0bb008dbcf..a4a0a566b1 100644
--- a/economy.c
+++ b/economy.c
@@ -28,6 +28,7 @@
 #include "ai/ai.h"
 #include "train.h"
 #include "newgrf_engine.h"
+#include "unmovable.h"
 
 // Score info
 const ScoreInfo _score_info[] = {
@@ -45,35 +46,6 @@ const ScoreInfo _score_info[] = {
 
 int _score_part[MAX_PLAYERS][NUM_SCORE];
 
-void UpdatePlayerHouse(Player *p, uint score)
-{
-	byte val;
-	TileIndex tile = p->location_of_house;
-
-	if (tile == 0)
-		return;
-
-	(val = 128, score < 170) ||
-	(val+= 4, score < 350) ||
-	(val+= 4, score < 520) ||
-	(val+= 4, score < 720) ||
-	(val+= 4, true);
-
-/* house is already big enough */
-	if (val <= _m[tile].m5)
-		return;
-
-	_m[tile + TileDiffXY(0, 0)].m5 =   val;
-	_m[tile + TileDiffXY(0, 1)].m5 = ++val;
-	_m[tile + TileDiffXY(1, 0)].m5 = ++val;
-	_m[tile + TileDiffXY(1, 1)].m5 = ++val;
-
-	MarkTileDirtyByTile(tile + TileDiffXY(0, 0));
-	MarkTileDirtyByTile(tile + TileDiffXY(0, 1));
-	MarkTileDirtyByTile(tile + TileDiffXY(1, 0));
-	MarkTileDirtyByTile(tile + TileDiffXY(1, 1));
-}
-
 int64 CalculateCompanyValue(const Player* p)
 {
 	PlayerID owner = p->index;
@@ -258,7 +230,7 @@ int UpdateCompanyRatingAndValue(Player *p, bool update)
 
 	if (update) {
     	p->old_economy[0].performance_history = score;
-    	UpdatePlayerHouse(p, score);
+    	UpdateCompanyHQ(p, score);
     	p->old_economy[0].company_value = CalculateCompanyValue(p);
     }
 
diff --git a/economy.h b/economy.h
index 1167c68604..e3ff9e6cea 100644
--- a/economy.h
+++ b/economy.h
@@ -57,8 +57,6 @@ extern const ScoreInfo _score_info[];
 extern int _score_part[MAX_PLAYERS][NUM_SCORE];
 
 int UpdateCompanyRatingAndValue(Player *p, bool update);
-void UpdatePlayerHouse(Player *p, uint score);
-
 
 VARDEF Subsidy _subsidies[MAX_PLAYERS];
 Pair SetupSubsidyDecodeParam(const Subsidy* s, bool mode);
diff --git a/unmovable.h b/unmovable.h
new file mode 100644
index 0000000000..5cdc7eb882
--- /dev/null
+++ b/unmovable.h
@@ -0,0 +1,8 @@
+/* $Id */
+
+#ifndef UNMOVABLE_H
+#define UNMOVABLE_H
+
+void UpdateCompanyHQ(Player *p, uint score);
+
+#endif
diff --git a/unmovable_cmd.c b/unmovable_cmd.c
index 1b1de5876c..497a611676 100644
--- a/unmovable_cmd.c
+++ b/unmovable_cmd.c
@@ -59,6 +59,35 @@ static int32 DestroyCompanyHQ(TileIndex tile, uint32 flags)
 		return CalculateCompanyValue(p) / 100;
 }
 
+void UpdateCompanyHQ(Player *p, uint score)
+{
+	byte val;
+	TileIndex tile = p->location_of_house;
+
+	if (tile == 0)
+		return;
+
+	(val = 128, score < 170) ||
+	(val+= 4, score < 350) ||
+	(val+= 4, score < 520) ||
+	(val+= 4, score < 720) ||
+	(val+= 4, true);
+
+/* house is already big enough */
+	if (val <= _m[tile].m5)
+		return;
+
+	_m[tile + TileDiffXY(0, 0)].m5 =   val;
+	_m[tile + TileDiffXY(0, 1)].m5 = ++val;
+	_m[tile + TileDiffXY(1, 0)].m5 = ++val;
+	_m[tile + TileDiffXY(1, 1)].m5 = ++val;
+
+	MarkTileDirtyByTile(tile + TileDiffXY(0, 0));
+	MarkTileDirtyByTile(tile + TileDiffXY(0, 1));
+	MarkTileDirtyByTile(tile + TileDiffXY(1, 0));
+	MarkTileDirtyByTile(tile + TileDiffXY(1, 1));
+}
+
 /** Build or relocate the HQ. This depends if the HQ is already built or not
  * @param x,y the coordinates where the HQ will be built or relocated to
  * @param p1 unused
@@ -91,7 +120,7 @@ int32 CmdBuildCompanyHQ(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 
 		MakeCompanyHQ(tile, _current_player);
 
-		UpdatePlayerHouse(p, score);
+		UpdateCompanyHQ(p, score);
 		InvalidateWindow(WC_COMPANY, p->index);
 	}