diff --git a/src/newgrf.cpp b/src/newgrf.cpp
index 4ec1f05dc3..224e6ca6fc 100644
--- a/src/newgrf.cpp
+++ b/src/newgrf.cpp
@@ -1027,12 +1027,12 @@ static void FinaliseHouseArray()
 	 * On the other hand, why 1930? Just 'fix' the houses with the lowest
 	 * minimum introduction date to 0.
 	 */
-	for (const auto &file : _grf_files) {
+	for (auto &file : _grf_files) {
 		if (file.housespec.empty()) continue;
 
 		size_t num_houses = file.housespec.size();
 		for (size_t i = 0; i < num_houses; i++) {
-			HouseSpec *hs = file.housespec[i].get();
+			auto &hs = file.housespec[i];
 
 			if (hs == nullptr) continue;
 
@@ -1042,8 +1042,12 @@ static void FinaliseHouseArray()
 
 			if (!IsHouseSpecValid(*hs, next1, next2, next3, file.filename)) continue;
 
-			_house_mngr.SetEntitySpec(hs);
+			_house_mngr.SetEntitySpec(std::move(*hs));
 		}
+
+		/* Won't be used again */
+		file.housespec.clear();
+		file.housespec.shrink_to_fit();
 	}
 
 	for (size_t i = 0; i < HouseSpec::Specs().size(); i++) {
@@ -1096,18 +1100,24 @@ static void FinaliseHouseArray()
  */
 static void FinaliseIndustriesArray()
 {
-	for (const auto &file : _grf_files) {
-		for (const auto &indsp : file.industryspec) {
+	for (auto &file : _grf_files) {
+		for (auto &indsp : file.industryspec) {
 			if (indsp == nullptr || !indsp->enabled) continue;
 
-			_industry_mngr.SetEntitySpec(indsp.get());
+			_industry_mngr.SetEntitySpec(std::move(*indsp));
 		}
 
-		for (const auto &indtsp : file.indtspec) {
+		for (auto &indtsp : file.indtspec) {
 			if (indtsp != nullptr) {
-				_industile_mngr.SetEntitySpec(indtsp.get());
+				_industile_mngr.SetEntitySpec(std::move(*indtsp));
 			}
 		}
+
+		/* Won't be used again */
+		file.industryspec.clear();
+		file.industryspec.shrink_to_fit();
+		file.indtspec.clear();
+		file.indtspec.shrink_to_fit();
 	}
 
 	for (auto &indsp : _industry_specs) {
@@ -1144,12 +1154,16 @@ static void FinaliseIndustriesArray()
  */
 static void FinaliseObjectsArray()
 {
-	for (const auto &file : _grf_files) {
+	for (auto &file : _grf_files) {
 		for (auto &objectspec : file.objectspec) {
 			if (objectspec != nullptr && objectspec->grf_prop.HasGrfFile() && objectspec->IsEnabled()) {
-				_object_mngr.SetEntitySpec(objectspec.get());
+				_object_mngr.SetEntitySpec(std::move(*objectspec));
 			}
 		}
+
+		/* Won't be used again */
+		file.objectspec.clear();
+		file.objectspec.shrink_to_fit();
 	}
 
 	ObjectSpec::BindToClasses();
@@ -1162,18 +1176,24 @@ static void FinaliseObjectsArray()
  */
 static void FinaliseAirportsArray()
 {
-	for (const auto &file : _grf_files) {
+	for (auto &file : _grf_files) {
 		for (auto &as : file.airportspec) {
 			if (as != nullptr && as->enabled) {
-				_airport_mngr.SetEntitySpec(as.get());
+				_airport_mngr.SetEntitySpec(std::move(*as));
 			}
 		}
 
 		for (auto &ats : file.airtspec) {
 			if (ats != nullptr && ats->enabled) {
-				_airporttile_mngr.SetEntitySpec(ats.get());
+				_airporttile_mngr.SetEntitySpec(std::move(*ats));
 			}
 		}
+
+		/* Won't be used again */
+		file.airportspec.clear();
+		file.airportspec.shrink_to_fit();
+		file.airtspec.clear();
+		file.airtspec.shrink_to_fit();
 	}
 }
 
diff --git a/src/newgrf_airport.cpp b/src/newgrf_airport.cpp
index fdd5fc3739..a22e87bb9d 100644
--- a/src/newgrf_airport.cpp
+++ b/src/newgrf_airport.cpp
@@ -134,22 +134,22 @@ void BindAirportSpecs()
 }
 
 
-void AirportOverrideManager::SetEntitySpec(AirportSpec *as)
+void AirportOverrideManager::SetEntitySpec(AirportSpec &&as)
 {
-	uint8_t airport_id = this->AddEntityID(as->grf_prop.local_id, as->grf_prop.grfid, as->grf_prop.subst_id);
+	uint8_t airport_id = this->AddEntityID(as.grf_prop.local_id, as.grf_prop.grfid, as.grf_prop.subst_id);
 
 	if (airport_id == this->invalid_id) {
 		GrfMsg(1, "Airport.SetEntitySpec: Too many airports allocated. Ignoring.");
 		return;
 	}
 
-	*AirportSpec::GetWithoutOverride(airport_id) = *as;
+	AirportSpec::specs[airport_id] = std::move(as);
 
 	/* Now add the overrides. */
 	for (int i = 0; i < this->max_offset; i++) {
 		AirportSpec *overridden_as = AirportSpec::GetWithoutOverride(i);
 
-		if (this->entity_overrides[i] != as->grf_prop.local_id || this->grfid_overrides[i] != as->grf_prop.grfid) continue;
+		if (this->entity_overrides[i] != AirportSpec::specs[airport_id].grf_prop.local_id || this->grfid_overrides[i] != AirportSpec::specs[airport_id].grf_prop.grfid) continue;
 
 		overridden_as->grf_prop.override_id = airport_id;
 		overridden_as->enabled = false;
diff --git a/src/newgrf_airport.h b/src/newgrf_airport.h
index f9faa33921..59e811b80e 100644
--- a/src/newgrf_airport.h
+++ b/src/newgrf_airport.h
@@ -141,6 +141,8 @@ struct AirportSpec : NewGRFSpecBase<AirportClassID> {
 
 private:
 	static AirportSpec specs[NUM_AIRPORTS]; ///< Specs of the airports.
+
+	friend void AirportOverrideManager::SetEntitySpec(AirportSpec &&as);
 };
 
 /** Information related to airport classes. */
diff --git a/src/newgrf_airporttiles.cpp b/src/newgrf_airporttiles.cpp
index f47e9e4af6..eea0f118c3 100644
--- a/src/newgrf_airporttiles.cpp
+++ b/src/newgrf_airporttiles.cpp
@@ -66,22 +66,22 @@ void AirportTileSpec::ResetAirportTiles()
 	_airporttile_mngr.ResetOverride();
 }
 
-void AirportTileOverrideManager::SetEntitySpec(const AirportTileSpec *airpts)
+void AirportTileOverrideManager::SetEntitySpec(AirportTileSpec &&airpts)
 {
-	StationGfx airpt_id = this->AddEntityID(airpts->grf_prop.local_id, airpts->grf_prop.grfid, airpts->grf_prop.subst_id);
+	StationGfx airpt_id = this->AddEntityID(airpts.grf_prop.local_id, airpts.grf_prop.grfid, airpts.grf_prop.subst_id);
 
 	if (airpt_id == this->invalid_id) {
 		GrfMsg(1, "AirportTile.SetEntitySpec: Too many airport tiles allocated. Ignoring.");
 		return;
 	}
 
-	AirportTileSpec::tiles[airpt_id] = *airpts;
+	AirportTileSpec::tiles[airpt_id] = std::move(airpts);
 
 	/* Now add the overrides. */
 	for (int i = 0; i < this->max_offset; i++) {
 		AirportTileSpec *overridden_airpts = &AirportTileSpec::tiles[i];
 
-		if (this->entity_overrides[i] != airpts->grf_prop.local_id || this->grfid_overrides[i] != airpts->grf_prop.grfid) continue;
+		if (this->entity_overrides[i] != AirportTileSpec::tiles[airpt_id].grf_prop.local_id || this->grfid_overrides[i] != AirportTileSpec::tiles[airpt_id].grf_prop.grfid) continue;
 
 		overridden_airpts->grf_prop.override_id = airpt_id;
 		overridden_airpts->enabled = false;
diff --git a/src/newgrf_airporttiles.h b/src/newgrf_airporttiles.h
index 1f2d989c33..68a62d1b07 100644
--- a/src/newgrf_airporttiles.h
+++ b/src/newgrf_airporttiles.h
@@ -84,7 +84,7 @@ struct AirportTileSpec {
 private:
 	static AirportTileSpec tiles[NUM_AIRPORTTILES];
 
-	friend void AirportTileOverrideManager::SetEntitySpec(const AirportTileSpec *airpts);
+	friend void AirportTileOverrideManager::SetEntitySpec(AirportTileSpec &&airpts);
 };
 
 void AnimateAirportTile(TileIndex tile);
diff --git a/src/newgrf_commons.cpp b/src/newgrf_commons.cpp
index 6ed612ca81..a46b5477d6 100644
--- a/src/newgrf_commons.cpp
+++ b/src/newgrf_commons.cpp
@@ -157,9 +157,9 @@ uint16_t OverrideManagerBase::GetSubstituteID(uint16_t entity_id) const
  * It will find itself the proper slot on which it will go
  * @param hs HouseSpec read from the grf file, ready for inclusion
  */
-void HouseOverrideManager::SetEntitySpec(const HouseSpec *hs)
+void HouseOverrideManager::SetEntitySpec(HouseSpec &&hs)
 {
-	HouseID house_id = this->AddEntityID(hs->grf_prop.local_id, hs->grf_prop.grfid, hs->grf_prop.subst_id);
+	HouseID house_id = this->AddEntityID(hs.grf_prop.local_id, hs.grf_prop.grfid, hs.grf_prop.subst_id);
 
 	if (house_id == this->invalid_id) {
 		GrfMsg(1, "House.SetEntitySpec: Too many houses allocated. Ignoring.");
@@ -170,13 +170,13 @@ void HouseOverrideManager::SetEntitySpec(const HouseSpec *hs)
 
 	/* Now that we know we can use the given id, copy the spec to its final destination. */
 	if (house_id >= house_specs.size()) house_specs.resize(house_id + 1);
-	house_specs[house_id] = *hs;
+	house_specs[house_id] = std::move(hs);
 
 	/* Now add the overrides. */
 	for (int i = 0; i < this->max_offset; i++) {
 		HouseSpec *overridden_hs = HouseSpec::Get(i);
 
-		if (this->entity_overrides[i] != hs->grf_prop.local_id || this->grfid_overrides[i] != hs->grf_prop.grfid) continue;
+		if (this->entity_overrides[i] != house_specs[house_id].grf_prop.local_id || this->grfid_overrides[i] != house_specs[house_id].grf_prop.grfid) continue;
 
 		overridden_hs->grf_prop.override_id = house_id;
 		this->entity_overrides[i] = this->invalid_id;
@@ -245,18 +245,18 @@ uint16_t IndustryOverrideManager::AddEntityID(uint16_t grf_local_id, uint32_t gr
  * checking what is available
  * @param inds Industryspec that comes from the grf decoding process
  */
-void IndustryOverrideManager::SetEntitySpec(IndustrySpec *inds)
+void IndustryOverrideManager::SetEntitySpec(IndustrySpec &&inds)
 {
 	/* First step : We need to find if this industry is already specified in the savegame data. */
-	IndustryType ind_id = this->GetID(inds->grf_prop.local_id, inds->grf_prop.grfid);
+	IndustryType ind_id = this->GetID(inds.grf_prop.local_id, inds.grf_prop.grfid);
 
 	if (ind_id == this->invalid_id) {
 		/* Not found.
 		 * Or it has already been overridden, so you've lost your place.
 		 * Or it is a simple substitute.
 		 * We need to find a free available slot */
-		ind_id = this->AddEntityID(inds->grf_prop.local_id, inds->grf_prop.grfid, inds->grf_prop.subst_id);
-		inds->grf_prop.override_id = this->invalid_id;  // make sure it will not be detected as overridden
+		ind_id = this->AddEntityID(inds.grf_prop.local_id, inds.grf_prop.grfid, inds.grf_prop.subst_id);
+		inds.grf_prop.override_id = this->invalid_id;  // make sure it will not be detected as overridden
 	}
 
 	if (ind_id == this->invalid_id) {
@@ -265,27 +265,27 @@ void IndustryOverrideManager::SetEntitySpec(IndustrySpec *inds)
 	}
 
 	/* Now that we know we can use the given id, copy the spec to its final destination... */
-	_industry_specs[ind_id] = *inds;
+	_industry_specs[ind_id] = std::move(inds);
 	/* ... and mark it as usable*/
 	_industry_specs[ind_id].enabled = true;
 }
 
-void IndustryTileOverrideManager::SetEntitySpec(const IndustryTileSpec *its)
+void IndustryTileOverrideManager::SetEntitySpec(IndustryTileSpec &&its)
 {
-	IndustryGfx indt_id = this->AddEntityID(its->grf_prop.local_id, its->grf_prop.grfid, its->grf_prop.subst_id);
+	IndustryGfx indt_id = this->AddEntityID(its.grf_prop.local_id, its.grf_prop.grfid, its.grf_prop.subst_id);
 
 	if (indt_id == this->invalid_id) {
 		GrfMsg(1, "IndustryTile.SetEntitySpec: Too many industry tiles allocated. Ignoring.");
 		return;
 	}
 
-	_industry_tile_specs[indt_id] = *its;
+	_industry_tile_specs[indt_id] = std::move(its);
 
 	/* Now add the overrides. */
 	for (int i = 0; i < this->max_offset; i++) {
 		IndustryTileSpec *overridden_its = &_industry_tile_specs[i];
 
-		if (this->entity_overrides[i] != its->grf_prop.local_id || this->grfid_overrides[i] != its->grf_prop.grfid) continue;
+		if (this->entity_overrides[i] != _industry_tile_specs[indt_id].grf_prop.local_id || this->grfid_overrides[i] != _industry_tile_specs[indt_id].grf_prop.grfid) continue;
 
 		overridden_its->grf_prop.override_id = indt_id;
 		overridden_its->enabled = false;
@@ -300,17 +300,17 @@ void IndustryTileOverrideManager::SetEntitySpec(const IndustryTileSpec *its)
  * checking what is available
  * @param spec ObjectSpec that comes from the grf decoding process
  */
-void ObjectOverrideManager::SetEntitySpec(ObjectSpec *spec)
+void ObjectOverrideManager::SetEntitySpec(ObjectSpec &&spec)
 {
 	/* First step : We need to find if this object is already specified in the savegame data. */
-	ObjectType type = this->GetID(spec->grf_prop.local_id, spec->grf_prop.grfid);
+	ObjectType type = this->GetID(spec.grf_prop.local_id, spec.grf_prop.grfid);
 
 	if (type == this->invalid_id) {
 		/* Not found.
 		 * Or it has already been overridden, so you've lost your place.
 		 * Or it is a simple substitute.
 		 * We need to find a free available slot */
-		type = this->AddEntityID(spec->grf_prop.local_id, spec->grf_prop.grfid, OBJECT_TRANSMITTER);
+		type = this->AddEntityID(spec.grf_prop.local_id, spec.grf_prop.grfid, OBJECT_TRANSMITTER);
 	}
 
 	if (type == this->invalid_id) {
@@ -322,7 +322,7 @@ void ObjectOverrideManager::SetEntitySpec(ObjectSpec *spec)
 
 	/* Now that we know we can use the given id, copy the spec to its final destination. */
 	if (type >= _object_specs.size()) _object_specs.resize(type + 1);
-	_object_specs[type] = *spec;
+	_object_specs[type] = std::move(spec);
 }
 
 /**
diff --git a/src/newgrf_commons.h b/src/newgrf_commons.h
index 37ecc134e7..d553bd6e49 100644
--- a/src/newgrf_commons.h
+++ b/src/newgrf_commons.h
@@ -210,7 +210,7 @@ public:
 	HouseOverrideManager(uint16_t offset, uint16_t maximum, uint16_t invalid) :
 			OverrideManagerBase(offset, maximum, invalid) {}
 
-	void SetEntitySpec(const HouseSpec *hs);
+	void SetEntitySpec(HouseSpec &&hs);
 };
 
 
@@ -223,7 +223,7 @@ public:
 	uint16_t AddEntityID(uint16_t grf_local_id, uint32_t grfid, uint16_t substitute_id) override;
 	uint16_t GetID(uint16_t grf_local_id, uint32_t grfid) const override;
 
-	void SetEntitySpec(IndustrySpec *inds);
+	void SetEntitySpec(IndustrySpec &&inds);
 };
 
 
@@ -235,7 +235,7 @@ public:
 	IndustryTileOverrideManager(uint16_t offset, uint16_t maximum, uint16_t invalid) :
 			OverrideManagerBase(offset, maximum, invalid) {}
 
-	void SetEntitySpec(const IndustryTileSpec *indts);
+	void SetEntitySpec(IndustryTileSpec &&indts);
 };
 
 struct AirportSpec;
@@ -244,7 +244,7 @@ public:
 	AirportOverrideManager(uint16_t offset, uint16_t maximum, uint16_t invalid) :
 			OverrideManagerBase(offset, maximum, invalid) {}
 
-	void SetEntitySpec(AirportSpec *inds);
+	void SetEntitySpec(AirportSpec &&inds);
 };
 
 struct AirportTileSpec;
@@ -255,7 +255,7 @@ public:
 	AirportTileOverrideManager(uint16_t offset, uint16_t maximum, uint16_t invalid) :
 			OverrideManagerBase(offset, maximum, invalid) {}
 
-	void SetEntitySpec(const AirportTileSpec *ats);
+	void SetEntitySpec(AirportTileSpec &&ats);
 };
 
 struct ObjectSpec;
@@ -266,7 +266,7 @@ public:
 	ObjectOverrideManager(uint16_t offset, uint16_t maximum, uint16_t invalid) :
 			OverrideManagerBase(offset, maximum, invalid) {}
 
-	void SetEntitySpec(ObjectSpec *spec);
+	void SetEntitySpec(ObjectSpec &&spec);
 };
 
 extern HouseOverrideManager _house_mngr;