--- a/src/ground_vehicle.hpp
+++ b/src/ground_vehicle.hpp
@@ -243,19 +243,6 @@
 	}
 
 	/**
-	 * Enum to handle ground vehicle subtypes.
-	 * Do not access it directly unless you have to. Use the subtype access functions.
-	 */
-	enum GroundVehicleSubtypeFlags {
-		GVSF_FRONT            = 0, ///< Leading engine of a consist.
-		GVSF_ARTICULATED_PART = 1, ///< Articulated part of an engine.
-		GVSF_WAGON            = 2, ///< Wagon (not used for road vehicles).
-		GVSF_ENGINE           = 3, ///< Engine that can be front engine, but might be placed behind another engine (not used for road vehicles).
-		GVSF_FREE_WAGON       = 4, ///< First in a wagon chain (in depot) (not used for road vehicles).
-		GVSF_MULTIHEADED      = 5, ///< Engine is multiheaded (not used for road vehicles).
-	};
-
-	/**
 	 * Set front engine state.
 	 */
 	FORCEINLINE void SetFrontEngine() { SetBit(this->subtype, GVSF_FRONT); }

--- a/src/vehicle_base.h
+++ b/src/vehicle_base.h
@@ -84,6 +84,20 @@
 	VE_DEFAULT = 0xFF,          ///< Default value to indicate that visual effect should be based on engine class
 };
 
+/**
+ * Enum to handle ground vehicle subtypes.
+ * This is defined here instead of at #GroundVehicle because some common function require access to these flags.
+ * Do not access it directly unless you have to. Use the subtype access functions.
+ */
+enum GroundVehicleSubtypeFlags {
+	GVSF_FRONT            = 0, ///< Leading engine of a consist.
+	GVSF_ARTICULATED_PART = 1, ///< Articulated part of an engine.
+	GVSF_WAGON            = 2, ///< Wagon (not used for road vehicles).
+	GVSF_ENGINE           = 3, ///< Engine that can be front engine, but might be placed behind another engine (not used for road vehicles).
+	GVSF_FREE_WAGON       = 4, ///< First in a wagon chain (in depot) (not used for road vehicles).
+	GVSF_MULTIHEADED      = 5, ///< Engine is multiheaded (not used for road vehicles).
+};
+
 /** Cached often queried values common to all vehicles. */
 struct VehicleCache {
 	uint16 cached_max_speed; ///< Maximum speed of the consist (minimum of the max speed of all vehicles in the consist).