diff --git a/src/newgrf/newgrf_act3.cpp b/src/newgrf/newgrf_act3.cpp
index 906b60d68f..faaa5660e0 100644
--- a/src/newgrf/newgrf_act3.cpp
+++ b/src/newgrf/newgrf_act3.cpp
@@ -394,7 +394,7 @@ static void ObjectMapSpriteGroup(ByteReader &buf, uint8_t idcount)
 				continue;
 			}
 
-			spec->grf_prop.SetSpriteGroup(OBJECT_SPRITE_GROUP_PURCHASE, _cur_gps.spritegroups[groupid]);
+			spec->grf_prop.SetSpriteGroup(StandardSpriteGroup::Purchase, _cur_gps.spritegroups[groupid]);
 		}
 	}
 
@@ -414,7 +414,7 @@ static void ObjectMapSpriteGroup(ByteReader &buf, uint8_t idcount)
 			continue;
 		}
 
-		spec->grf_prop.SetSpriteGroup(OBJECT_SPRITE_GROUP_DEFAULT, _cur_gps.spritegroups[groupid]);
+		spec->grf_prop.SetSpriteGroup(StandardSpriteGroup::Default, _cur_gps.spritegroups[groupid]);
 		spec->grf_prop.SetGRFFile(_cur_gps.grffile);
 		spec->grf_prop.local_id = object;
 	}
diff --git a/src/newgrf_commons.h b/src/newgrf_commons.h
index 7be4298a52..7cf7441b24 100644
--- a/src/newgrf_commons.h
+++ b/src/newgrf_commons.h
@@ -306,9 +306,10 @@ struct GRFFilePropsBase {
 
 /**
  * Fixed-length list of sprite groups for an entity.
+ * @tparam Tkey Key for indexing spritegroups
  * @tparam Tcount Number of spritegroups
  */
-template <size_t Tcount>
+template <class Tkey, size_t Tcount>
 struct FixedGRFFileProps : GRFFilePropsBase {
 	std::array<const struct SpriteGroup *, Tcount> spritegroups{}; ///< pointers to the different sprite groups of the entity
 
@@ -317,14 +318,14 @@ struct FixedGRFFileProps : GRFFilePropsBase {
 	 * @param index Index to get.
 	 * @returns SpriteGroup at index, or nullptr if not present.
 	 */
-	const struct SpriteGroup *GetSpriteGroup(size_t index = 0) const { return this->spritegroups[index]; }
+	const struct SpriteGroup *GetSpriteGroup(Tkey index) const { return this->spritegroups[static_cast<size_t>(index)]; }
 
 	/**
 	 * Set the SpriteGroup at the specified index.
 	 * @param index Index to set.
 	 * @param spritegroup SpriteGroup to set.
 	 */
-	void SetSpriteGroup(size_t index, const struct SpriteGroup *spritegroup) { this->spritegroups[index] = spritegroup; }
+	void SetSpriteGroup(Tkey index, const struct SpriteGroup *spritegroup) { this->spritegroups[static_cast<size_t>(index)] = spritegroup; }
 };
 
 /**
@@ -337,6 +338,16 @@ struct SingleGRFFileProps : GRFFilePropsBase {
 	void SetSpriteGroup(const struct SpriteGroup *spritegroup) { this->spritegroup = spritegroup; }
 };
 
+/**
+ * Standard sprite groups.
+ */
+enum class StandardSpriteGroup {
+	Default, ///< Default type used when no more-specific group matches.
+	Purchase, ///< Used before an entity exists.
+	End
+};
+using StandardGRFFileProps = FixedGRFFileProps<StandardSpriteGroup, static_cast<size_t>(StandardSpriteGroup::End)>;
+
 /**
  * Variable-length list of sprite groups for an entity.
  * @tparam Tkey Key for indexing spritegroups
diff --git a/src/newgrf_object.cpp b/src/newgrf_object.cpp
index 2369877377..cee3f0e1e8 100644
--- a/src/newgrf_object.cpp
+++ b/src/newgrf_object.cpp
@@ -386,8 +386,8 @@ ObjectResolverObject::ObjectResolverObject(const ObjectSpec *spec, Object *obj,
 		CallbackID callback, uint32_t param1, uint32_t param2)
 	: ResolverObject(spec->grf_prop.grffile, callback, param1, param2), object_scope(*this, obj, spec, tile, view)
 {
-	this->root_spritegroup = (obj == nullptr) ? spec->grf_prop.GetSpriteGroup(OBJECT_SPRITE_GROUP_PURCHASE) : nullptr;
-	if (this->root_spritegroup == nullptr) this->root_spritegroup = spec->grf_prop.GetSpriteGroup(OBJECT_SPRITE_GROUP_DEFAULT);
+	this->root_spritegroup = (obj == nullptr) ? spec->grf_prop.GetSpriteGroup(StandardSpriteGroup::Purchase) : nullptr;
+	if (this->root_spritegroup == nullptr) this->root_spritegroup = spec->grf_prop.GetSpriteGroup(StandardSpriteGroup::Default);
 }
 
 /**
diff --git a/src/newgrf_object.h b/src/newgrf_object.h
index e3c1a33069..7b0aff4938 100644
--- a/src/newgrf_object.h
+++ b/src/newgrf_object.h
@@ -58,8 +58,7 @@ DECLARE_INCREMENT_DECREMENT_OPERATORS(ObjectClassID)
  * default objects in table/object_land.h
  */
 struct ObjectSpec : NewGRFSpecBase<ObjectClassID> {
-	/* 2 because of the "normal" and "buy" sprite stacks. */
-	FixedGRFFileProps<2> grf_prop; ///< Properties related the the grf file
+	StandardGRFFileProps grf_prop; ///< Properties related the the grf file
 	/* Animation speed default differs from other features */
 	AnimationInfo<ObjectAnimationTriggers> animation{0, AnimationStatus::NoAnimation, 0, {}};  ///< Information about the animation.
 	StringID name;                ///< The name for this object.
@@ -166,9 +165,6 @@ private:
 /** Class containing information relating to object classes. */
 using ObjectClass = NewGRFClass<ObjectSpec, ObjectClassID, OBJECT_CLASS_MAX>;
 
-static const size_t OBJECT_SPRITE_GROUP_DEFAULT = 0;
-static const size_t OBJECT_SPRITE_GROUP_PURCHASE = 1;
-
 uint16_t GetObjectCallback(CallbackID callback, uint32_t param1, uint32_t param2, const ObjectSpec *spec, Object *o, TileIndex tile, uint8_t view = 0);
 
 void DrawNewObjectTile(TileInfo *ti, const ObjectSpec *spec);
diff --git a/src/table/object_land.h b/src/table/object_land.h
index 6988af7a72..47199bc0c9 100644
--- a/src/table/object_land.h
+++ b/src/table/object_land.h
@@ -106,7 +106,7 @@ static const DrawTileSpriteSpan _object_hq[] = {
 #undef TILE_SPRITE_LINE
 #undef TILE_SPRITE_LINE_NOTHING
 
-#define M(name, size, build_cost_multiplier, clear_cost_multiplier, height, climate, gen_amount, flags) {{INVALID_OBJECT_CLASS, 0}, FixedGRFFileProps<2>{}, AnimationInfo<ObjectAnimationTriggers>{}, name, climate, size, build_cost_multiplier, clear_cost_multiplier, TimerGameCalendar::Date{}, CalendarTime::MAX_DATE + 1, flags, ObjectCallbackMasks{}, height, 1, gen_amount, {}}
+#define M(name, size, build_cost_multiplier, clear_cost_multiplier, height, climate, gen_amount, flags) {{INVALID_OBJECT_CLASS, 0}, StandardGRFFileProps{}, AnimationInfo<ObjectAnimationTriggers>{}, name, climate, size, build_cost_multiplier, clear_cost_multiplier, TimerGameCalendar::Date{}, CalendarTime::MAX_DATE + 1, flags, ObjectCallbackMasks{}, height, 1, gen_amount, {}}
 
 /* Climates
  * T = Temperate