diff --git a/src/bridge.h b/src/bridge.h
--- a/src/bridge.h
+++ b/src/bridge.h
@@ -12,6 +12,7 @@
 
 #include "gfx_type.h"
 #include "tile_cmd.h"
+#include "timer/timer_game_calendar.h"
 
 /**
  * This enum is related to the definition of bridge pieces,
@@ -39,17 +40,17 @@ typedef uint BridgeType; ///< Bridge spe
  * Struct containing information about a single bridge type
  */
 struct BridgeSpec {
-	Year avail_year;             ///< the year where it becomes available
-	byte min_length;             ///< the minimum length (not counting start and end tile)
-	uint16 max_length;           ///< the maximum length (not counting start and end tile)
-	uint16 price;                ///< the price multiplier
-	uint16 speed;                ///< maximum travel speed (1 unit = 1/1.6 mph = 1 km-ish/h)
-	SpriteID sprite;             ///< the sprite which is used in the GUI
-	PaletteID pal;               ///< the palette which is used in the GUI
-	StringID material;           ///< the string that contains the bridge description
-	StringID transport_name[2];  ///< description of the bridge, when built for road or rail
-	PalSpriteID **sprite_table;  ///< table of sprites for drawing the bridge
-	byte flags;                  ///< bit 0 set: disable drawing of far pillars.
+	TimerGameCalendar::Year avail_year; ///< the year where it becomes available
+	byte min_length;                    ///< the minimum length (not counting start and end tile)
+	uint16 max_length;                  ///< the maximum length (not counting start and end tile)
+	uint16 price;                       ///< the price multiplier
+	uint16 speed;                       ///< maximum travel speed (1 unit = 1/1.6 mph = 1 km-ish/h)
+	SpriteID sprite;                    ///< the sprite which is used in the GUI
+	PaletteID pal;                      ///< the palette which is used in the GUI
+	StringID material;                  ///< the string that contains the bridge description
+	StringID transport_name[2];         ///< description of the bridge, when built for road or rail
+	PalSpriteID **sprite_table;         ///< table of sprites for drawing the bridge
+	byte flags;                         ///< bit 0 set: disable drawing of far pillars.
 };
 
 extern BridgeSpec _bridge[MAX_BRIDGES];