diff --git a/src/gamelog.cpp b/src/gamelog.cpp
index 6c3b08ac89..805a4a0992 100644
--- a/src/gamelog.cpp
+++ b/src/gamelog.cpp
@@ -507,7 +507,7 @@ bool Gamelog::GRFBugReverse(uint32_t grfid, uint16_t internal_id)
  */
 static inline bool IsLoggableGrfConfig(const GRFConfig &g)
 {
-	return !HasBit(g.flags, GCF_STATIC) && g.status != GCS_NOT_FOUND;
+	return !g.flags.Test(GRFConfigFlag::Static) && g.status != GCS_NOT_FOUND;
 }
 
 /**
diff --git a/src/gfxinit.cpp b/src/gfxinit.cpp
index 1cdb3206e4..c64ffc50f7 100644
--- a/src/gfxinit.cpp
+++ b/src/gfxinit.cpp
@@ -153,7 +153,7 @@ static std::unique_ptr<GRFConfig> GetDefaultExtraGRFConfig()
 	auto gc = std::make_unique<GRFConfig>("OPENTTD.GRF");
 	gc->palette |= GRFP_GRF_DOS;
 	FillGRFDetails(*gc, false, BASESET_DIR);
-	ClrBit(gc->flags, GCF_INIT_ONLY);
+	gc->flags.Reset(GRFConfigFlag::InitOnly);
 	return gc;
 }
 
@@ -165,7 +165,7 @@ static std::unique_ptr<GRFConfig> GetBasesetExtraGRFConfig()
 {
 	auto gc = std::make_unique<GRFConfig>(BaseGraphics::GetUsedSet()->GetOrCreateExtraConfig());
 	if (gc->param.empty()) gc->SetParameterDefaults();
-	ClrBit(gc->flags, GCF_INIT_ONLY);
+	gc->flags.Reset(GRFConfigFlag::InitOnly);
 	return gc;
 }
 
@@ -272,7 +272,7 @@ static bool SwitchNewGRFBlitter()
 	uint depth_wanted_by_base = BaseGraphics::GetUsedSet()->blitter == BLT_32BPP ? 32 : 8;
 	uint depth_wanted_by_grf = _support8bpp != S8BPP_NONE ? 8 : 32;
 	for (const auto &c : _grfconfig) {
-		if (c->status == GCS_DISABLED || c->status == GCS_NOT_FOUND || HasBit(c->flags, GCF_INIT_ONLY)) continue;
+		if (c->status == GCS_DISABLED || c->status == GCS_NOT_FOUND || c->flags.Test(GRFConfigFlag::InitOnly)) continue;
 		if (c->palette & GRFP_BLT_32BPP) depth_wanted_by_grf = 32;
 	}
 	/* We need a 32bpp blitter for font anti-alias. */
diff --git a/src/network/core/network_game_info.cpp b/src/network/core/network_game_info.cpp
index 2630efdbe0..35be747e63 100644
--- a/src/network/core/network_game_info.cpp
+++ b/src/network/core/network_game_info.cpp
@@ -193,7 +193,7 @@ static void HandleIncomingNetworkGameInfoGRFConfig(GRFConfig &config, std::strin
 		config.info = f->info;
 		config.url = f->url;
 	}
-	SetBit(config.flags, GCF_COPY);
+	config.flags.Set(GRFConfigFlag::Copy);
 }
 
 /**
@@ -230,12 +230,12 @@ void SerializeNetworkGameInfo(Packet &p, const NetworkServerGameInfo &info, bool
 		 * the GRFs that are needed, i.e. the ones that the server has
 		 * selected in the NewGRF GUI and not the ones that are used due
 		 * to the fact that they are in [newgrf-static] in openttd.cfg */
-		uint count = std::ranges::count_if(info.grfconfig, [](const auto &c) { return !HasBit(c->flags, GCF_STATIC); });
+		uint count = std::ranges::count_if(info.grfconfig, [](const auto &c) { return !c->flags.Test(GRFConfigFlag::Static); });
 		p.Send_uint8 (count); // Send number of GRFs
 
 		/* Send actual GRF Identifications */
 		for (const auto &c : info.grfconfig) {
-			if (HasBit(c->flags, GCF_STATIC)) continue;
+			if (c->flags.Test(GRFConfigFlag::Static)) continue;
 
 			SerializeGRFIdentifier(p, c->ident);
 			if (send_newgrf_names) p.Send_string(c->GetName());
diff --git a/src/network/network_gamelist.cpp b/src/network/network_gamelist.cpp
index afbc9e3ce9..f2c96c1ea0 100644
--- a/src/network/network_gamelist.cpp
+++ b/src/network/network_gamelist.cpp
@@ -118,7 +118,7 @@ void NetworkAfterNewGRFScan()
 		item->info.compatible = item->info.version_compatible;
 
 		for (auto &c : item->info.grfconfig) {
-			assert(HasBit(c->flags, GCF_COPY));
+			assert(c->flags.Test(GRFConfigFlag::Copy));
 
 			const GRFConfig *f = FindGRFConfig(c->ident.grfid, FGCM_EXACT, &c->ident.md5sum);
 			if (f == nullptr) {
diff --git a/src/network/network_server.cpp b/src/network/network_server.cpp
index b0d00477b7..1133ebd2ab 100644
--- a/src/network/network_server.cpp
+++ b/src/network/network_server.cpp
@@ -418,11 +418,11 @@ NetworkRecvStatus ServerNetworkGameSocketHandler::SendNewGRFCheck()
 
 	auto p = std::make_unique<Packet>(this, PACKET_SERVER_CHECK_NEWGRFS, TCP_MTU);
 
-	uint grf_count = std::ranges::count_if(_grfconfig, [](const auto &c){ return !HasBit(c->flags, GCF_STATIC); });
+	uint grf_count = std::ranges::count_if(_grfconfig, [](const auto &c){ return !c->flags.Test(GRFConfigFlag::Static); });
 	p->Send_uint8 (grf_count);
 
 	for (const auto &c : _grfconfig) {
-		if (!HasBit(c->flags, GCF_STATIC)) SerializeGRFIdentifier(*p, c->ident);
+		if (!c->flags.Test(GRFConfigFlag::Static)) SerializeGRFIdentifier(*p, c->ident);
 	}
 
 	this->SendPacket(std::move(p));
diff --git a/src/newgrf.cpp b/src/newgrf.cpp
index 84402c472a..698a8dc9b0 100644
--- a/src/newgrf.cpp
+++ b/src/newgrf.cpp
@@ -5063,7 +5063,7 @@ static void SafeChangeInfo(ByteReader &buf)
 				uint32_t s = buf.ReadDWord();
 				buf.ReadDWord(); // dest
 				const GRFConfig *grfconfig = GetGRFConfig(s);
-				if (grfconfig != nullptr && !HasBit(grfconfig->flags, GCF_STATIC)) {
+				if (grfconfig != nullptr && !grfconfig->flags.Test(GRFConfigFlag::Static)) {
 					is_safe = false;
 					break;
 				}
@@ -5072,7 +5072,7 @@ static void SafeChangeInfo(ByteReader &buf)
 		}
 	}
 
-	SetBit(_cur.grfconfig->flags, GCF_UNSAFE);
+	_cur.grfconfig->flags.Set(GRFConfigFlag::Unsafe);
 
 	/* Skip remainder of GRF */
 	_cur.skip_sprites = -1;
@@ -6376,7 +6376,7 @@ static void FeatureNewName(ByteReader &buf)
 			case GSF_SHIPS:
 			case GSF_AIRCRAFT:
 				if (!generic) {
-					Engine *e = GetNewEngine(_cur.grffile, (VehicleType)feature, id, HasBit(_cur.grfconfig->flags, GCF_STATIC));
+					Engine *e = GetNewEngine(_cur.grffile, (VehicleType)feature, id, _cur.grfconfig->flags.Test(GRFConfigFlag::Static));
 					if (e == nullptr) break;
 					StringID string = AddGRFString(_cur.grffile->grfid, GRFStringID{e->index}, lang, new_scheme, false, name, e->info.string_id);
 					e->info.string_id = string;
@@ -6517,7 +6517,7 @@ static void GraphicsNew(ByteReader &buf)
 	uint16_t offset = HasBit(type, 7) ? buf.ReadExtendedByte() : 0;
 	ClrBit(type, 7); // Clear the high bit as that only indicates whether there is an offset.
 
-	if ((type == 0x0D) && (num == 10) && HasBit(_cur.grfconfig->flags, GCF_SYSTEM)) {
+	if ((type == 0x0D) && (num == 10) && _cur.grfconfig->flags.Test(GRFConfigFlag::System)) {
 		/* Special not-TTDP-compatible case used in openttd.grf
 		 * Missing shore sprites and initialisation of SPR_SHORE_BASE */
 		GrfMsg(2, "GraphicsNew: Loading 10 missing shore sprites from extra grf.");
@@ -6979,7 +6979,7 @@ static void SkipIf(ByteReader &buf)
 
 		GRFConfig *c = GetGRFConfig(cond_val, mask);
 
-		if (c != nullptr && HasBit(c->flags, GCF_STATIC) && !HasBit(_cur.grfconfig->flags, GCF_STATIC) && _networking) {
+		if (c != nullptr && c->flags.Test(GRFConfigFlag::Static) && !_cur.grfconfig->flags.Test(GRFConfigFlag::Static) && _networking) {
 			DisableStaticNewGRFInfluencingNonStaticNewGRFs(*c);
 			c = nullptr;
 		}
@@ -7091,12 +7091,12 @@ static void ScanInfo(ByteReader &buf)
 	_cur.grfconfig->ident.grfid = grfid;
 
 	if (grf_version < 2 || grf_version > 8) {
-		SetBit(_cur.grfconfig->flags, GCF_INVALID);
+		_cur.grfconfig->flags.Set(GRFConfigFlag::Invalid);
 		Debug(grf, 0, "{}: NewGRF \"{}\" (GRFID {:08X}) uses GRF version {}, which is incompatible with this version of OpenTTD.", _cur.grfconfig->filename, StrMakeValid(name), std::byteswap(grfid), grf_version);
 	}
 
 	/* GRF IDs starting with 0xFF are reserved for internal TTDPatch use */
-	if (GB(grfid, 0, 8) == 0xFF) SetBit(_cur.grfconfig->flags, GCF_SYSTEM);
+	if (GB(grfid, 0, 8) == 0xFF) _cur.grfconfig->flags.Set(GRFConfigFlag::System);
 
 	AddGRFTextToList(_cur.grfconfig->name, 0x7F, grfid, false, name);
 
@@ -7351,7 +7351,7 @@ static void SafeParamSet(ByteReader &buf)
 	 * reserved, it would be marked unsafe anyway. GRM for (e.g. bridge)
 	 * sprites  is considered safe. */
 
-	SetBit(_cur.grfconfig->flags, GCF_UNSAFE);
+	_cur.grfconfig->flags.Set(GRFConfigFlag::Unsafe);
 
 	/* Skip remainder of GRF */
 	_cur.skip_sprites = -1;
@@ -7620,7 +7620,7 @@ static void ParamSet(ByteReader &buf)
 			/* Read another GRF File's parameter */
 			const GRFFile *file = GetFileByGRFID(data);
 			GRFConfig *c = GetGRFConfig(data);
-			if (c != nullptr && HasBit(c->flags, GCF_STATIC) && !HasBit(_cur.grfconfig->flags, GCF_STATIC) && _networking) {
+			if (c != nullptr && c->flags.Test(GRFConfigFlag::Static) && !_cur.grfconfig->flags.Test(GRFConfigFlag::Static) && _networking) {
 				/* Disable the read GRF if it is a static NewGRF. */
 				DisableStaticNewGRFInfluencingNonStaticNewGRFs(*c);
 				src1 = 0;
@@ -7759,7 +7759,7 @@ static void ParamSet(ByteReader &buf)
 			ClrBit(res, GMB_TRAIN_WIDTH_32_PIXELS);
 
 			/* Only copy safe bits for static grfs */
-			if (HasBit(_cur.grfconfig->flags, GCF_STATIC)) {
+			if (_cur.grfconfig->flags.Test(GRFConfigFlag::Static)) {
 				uint32_t safe_bits = 0;
 				SetBit(safe_bits, GMB_SECOND_ROCKY_TILE_SET);
 
@@ -7800,7 +7800,7 @@ static void SafeGRFInhibit(ByteReader &buf)
 
 		/* GRF is unsafe it if tries to deactivate other GRFs */
 		if (grfid != _cur.grfconfig->ident.grfid) {
-			SetBit(_cur.grfconfig->flags, GCF_UNSAFE);
+			_cur.grfconfig->flags.Set(GRFConfigFlag::Unsafe);
 
 			/* Skip remainder of GRF */
 			_cur.skip_sprites = -1;
@@ -8636,7 +8636,7 @@ static void StaticGRFInfo(ByteReader &buf)
  */
 static void GRFUnsafe(ByteReader &)
 {
-	SetBit(_cur.grfconfig->flags, GCF_UNSAFE);
+	_cur.grfconfig->flags.Set(GRFConfigFlag::Unsafe);
 
 	/* Skip remainder of GRF */
 	_cur.skip_sprites = -1;
@@ -9757,7 +9757,7 @@ void LoadNewGRFFile(GRFConfig &config, GrfLoadingStage stage, Subdirectory subdi
 		_cur.grffile = GetFileByFilename(filename);
 		if (_cur.grffile == nullptr) UserError("File '{}' lost in cache.\n", filename);
 		if (stage == GLS_RESERVE && config.status != GCS_INITIALISED) return;
-		if (stage == GLS_ACTIVATION && !HasBit(config.flags, GCF_RESERVED)) return;
+		if (stage == GLS_ACTIVATION && !config.flags.Test(GRFConfigFlag::Reserved)) return;
 	}
 
 	bool needs_palette_remap = config.palette & GRFP_USE_MASK;
@@ -10141,7 +10141,7 @@ void LoadNewGRF(SpriteID load_index, uint num_baseset)
 		_cur.stage = stage;
 		for (const auto &c : _grfconfig) {
 			if (c->status == GCS_DISABLED || c->status == GCS_NOT_FOUND) continue;
-			if (stage > GLS_INIT && HasBit(c->flags, GCF_INIT_ONLY)) continue;
+			if (stage > GLS_INIT && c->flags.Test(GRFConfigFlag::InitOnly)) continue;
 
 			Subdirectory subdir = num_grfs < num_baseset ? BASESET_DIR : NEWGRF_DIR;
 			if (!FioCheckFileExists(c->filename, subdir)) {
@@ -10152,7 +10152,7 @@ void LoadNewGRF(SpriteID load_index, uint num_baseset)
 
 			if (stage == GLS_LABELSCAN) InitNewGRFFile(*c);
 
-			if (!HasBit(c->flags, GCF_STATIC) && !HasBit(c->flags, GCF_SYSTEM)) {
+			if (!c->flags.Test(GRFConfigFlag::Static) && !c->flags.Test(GRFConfigFlag::System)) {
 				if (num_non_static == NETWORK_MAX_GRF_COUNT) {
 					Debug(grf, 0, "'{}' is not loaded as the maximum number of non-static GRFs has been reached", c->filename);
 					c->status = GCS_DISABLED;
@@ -10166,14 +10166,14 @@ void LoadNewGRF(SpriteID load_index, uint num_baseset)
 
 			LoadNewGRFFile(*c, stage, subdir, false);
 			if (stage == GLS_RESERVE) {
-				SetBit(c->flags, GCF_RESERVED);
+				c->flags.Set(GRFConfigFlag::Reserved);
 			} else if (stage == GLS_ACTIVATION) {
-				ClrBit(c->flags, GCF_RESERVED);
+				c->flags.Reset(GRFConfigFlag::Reserved);
 				assert(GetFileByGRFID(c->ident.grfid) == _cur.grffile);
 				ClearTemporaryNewGRFData(_cur.grffile);
 				BuildCargoTranslationMap();
 				Debug(sprite, 2, "LoadNewGRF: Currently {} sprites are loaded", _cur.spriteid);
-			} else if (stage == GLS_INIT && HasBit(c->flags, GCF_INIT_ONLY)) {
+			} else if (stage == GLS_INIT && c->flags.Test(GRFConfigFlag::InitOnly)) {
 				/* We're not going to activate this, so free whatever data we allocated */
 				ClearTemporaryNewGRFData(_cur.grffile);
 			}
diff --git a/src/newgrf_config.cpp b/src/newgrf_config.cpp
index 98191302f8..0e7ab0d289 100644
--- a/src/newgrf_config.cpp
+++ b/src/newgrf_config.cpp
@@ -43,7 +43,7 @@ GRFConfig::GRFConfig(const GRFConfig &config) :
 	error(config.error),
 	version(config.version),
 	min_loadable_version(config.min_loadable_version),
-	flags(config.flags & ~(1 << GCF_COPY)),
+	flags(config.flags),
 	status(config.status),
 	grf_bugs(config.grf_bugs),
 	num_valid_params(config.num_valid_params),
@@ -52,6 +52,7 @@ GRFConfig::GRFConfig(const GRFConfig &config) :
 	param_info(config.param_info),
 	param(config.param)
 {
+	this->flags.Reset(GRFConfigFlag::Copy);
 }
 
 void GRFConfig::SetParams(std::span<const uint32_t> pars)
@@ -306,14 +307,14 @@ bool FillGRFDetails(GRFConfig &config, bool is_static, Subdirectory subdir)
 	config.FinalizeParameterInfo();
 
 	/* Skip if the grfid is 0 (not read) or if it is an internal GRF */
-	if (config.ident.grfid == 0 || HasBit(config.flags, GCF_SYSTEM)) return false;
+	if (config.ident.grfid == 0 || config.flags.Test(GRFConfigFlag::System)) return false;
 
 	if (is_static) {
 		/* Perform a 'safety scan' for static GRFs */
 		LoadNewGRFFile(config, GLS_SAFETYSCAN, subdir, true);
 
-		/* GCF_UNSAFE is set if GLS_SAFETYSCAN finds unsafe actions */
-		if (HasBit(config.flags, GCF_UNSAFE)) return false;
+		/* GRFConfigFlag::Unsafe is set if GLS_SAFETYSCAN finds unsafe actions */
+		if (config.flags.Test(GRFConfigFlag::Unsafe)) return false;
 	}
 
 	return CalcGRFMD5Sum(config, subdir);
@@ -340,7 +341,11 @@ static void AppendGRFConfigList(GRFConfigList &dst, const GRFConfigList &src, bo
 {
 	for (const auto &s : src) {
 		auto &c = dst.emplace_back(std::make_unique<GRFConfig>(*s));
-		AssignBit(c->flags, GCF_INIT_ONLY, init_only);
+		if (init_only) {
+			c->flags.Set(GRFConfigFlag::InitOnly);
+		} else {
+			c->flags.Reset(GRFConfigFlag::InitOnly);
+		}
 	}
 }
 
@@ -428,15 +433,15 @@ GRFListCompatibility IsGoodGRFConfigList(GRFConfigList &grfconfig)
 
 	for (auto &c : grfconfig) {
 		const GRFConfig *f = FindGRFConfig(c->ident.grfid, FGCM_EXACT, &c->ident.md5sum);
-		if (f == nullptr || HasBit(f->flags, GCF_INVALID)) {
+		if (f == nullptr || f->flags.Test(GRFConfigFlag::Invalid)) {
 			/* If we have not found the exactly matching GRF try to find one with the
 			 * same grfid, as it most likely is compatible */
 			f = FindGRFConfig(c->ident.grfid, FGCM_COMPATIBLE, nullptr, c->version);
 			if (f != nullptr) {
 				Debug(grf, 1, "NewGRF {:08X} ({}) not found; checksum {}. Compatibility mode on", std::byteswap(c->ident.grfid), c->filename, FormatArrayAsHex(c->ident.md5sum));
-				if (!HasBit(c->flags, GCF_COMPATIBLE)) {
+				if (!c->flags.Test(GRFConfigFlag::Compatible)) {
 					/* Preserve original_md5sum after it has been assigned */
-					SetBit(c->flags, GCF_COMPATIBLE);
+					c->flags.Set(GRFConfigFlag::Compatible);
 					c->original_md5sum = c->ident.md5sum;
 				}
 
@@ -456,9 +461,9 @@ compatible_grf:
 			/* The filename could be the filename as in the savegame. As we need
 			 * to load the GRF here, we need the correct filename, so overwrite that
 			 * in any case and set the name and info when it is not set already.
-			 * When the GCF_COPY flag is set, it is certain that the filename is
+			 * When the GRFConfigFlag::Copy flag is set, it is certain that the filename is
 			 * already a local one, so there is no need to replace it. */
-			if (!HasBit(c->flags, GCF_COPY)) {
+			if (!c->flags.Test(GRFConfigFlag::Copy)) {
 				c->filename = f->filename;
 				c->ident.md5sum = f->ident.md5sum;
 				c->name = f->name;
@@ -605,7 +610,7 @@ const GRFConfig *FindGRFConfig(uint32_t grfid, FindGRFConfigMode mode, const MD5
 		/* return it, if the exact same newgrf is found, or if we do not care about finding "the best" */
 		if (md5sum != nullptr || mode == FGCM_ANY) return c.get();
 		/* Skip incompatible stuff, unless explicitly allowed */
-		if (mode != FGCM_NEWEST && HasBit(c->flags, GCF_INVALID)) continue;
+		if (mode != FGCM_NEWEST && c->flags.Test(GRFConfigFlag::Invalid)) continue;
 		/* check version compatibility */
 		if (mode == FGCM_COMPATIBLE && !c->IsCompatible(desired_version)) continue;
 		/* remember the newest one as "the best" */
diff --git a/src/newgrf_config.h b/src/newgrf_config.h
index 77436a84a5..4b67eb2a0f 100644
--- a/src/newgrf_config.h
+++ b/src/newgrf_config.h
@@ -17,16 +17,17 @@
 #include "3rdparty/md5/md5.h"
 
 /** GRF config bit flags */
-enum GCF_Flags : uint8_t {
-	GCF_SYSTEM,     ///< GRF file is an openttd-internal system grf
-	GCF_UNSAFE,     ///< GRF file is unsafe for static usage
-	GCF_STATIC,     ///< GRF file is used statically (can be used in any MP game)
-	GCF_COMPATIBLE, ///< GRF file does not exactly match the requested GRF (different MD5SUM), but grfid matches)
-	GCF_COPY,       ///< The data is copied from a grf in _all_grfs
-	GCF_INIT_ONLY,  ///< GRF file is processed up to GLS_INIT
-	GCF_RESERVED,   ///< GRF file passed GLS_RESERVE stage
-	GCF_INVALID,    ///< GRF is unusable with this version of OpenTTD
+enum GRFConfigFlag : uint8_t {
+	System,     ///< GRF file is an openttd-internal system grf
+	Unsafe,     ///< GRF file is unsafe for static usage
+	Static,     ///< GRF file is used statically (can be used in any MP game)
+	Compatible, ///< GRF file does not exactly match the requested GRF (different MD5SUM), but grfid matches)
+	Copy,       ///< The data is copied from a grf in _all_grfs
+	InitOnly,   ///< GRF file is processed up to GLS_INIT
+	Reserved,   ///< GRF file passed GLS_RESERVE stage
+	Invalid,    ///< GRF is unusable with this version of OpenTTD
 };
+using GRFConfigFlags = EnumBitSet<GRFConfigFlag, uint8_t>;
 
 /** Status of GRF */
 enum GRFStatus : uint8_t {
@@ -172,7 +173,7 @@ struct GRFConfig {
 
 	uint32_t version = 0; ///< NOSAVE: Version a NewGRF can set so only the newest NewGRF is shown
 	uint32_t min_loadable_version = 0; ///< NOSAVE: Minimum compatible version a NewGRF can define
-	uint8_t flags = 0; ///< NOSAVE: GCF_Flags, bitset
+	GRFConfigFlags flags = {}; ///< NOSAVE: GCF_Flags, bitset
 	GRFStatus status = GCS_UNKNOWN; ///< NOSAVE: GRFStatus, enum
 	GRFBugs grf_bugs = {}; ///< NOSAVE: bugs in this GRF in this run, @see enum GRFBugs
 	uint8_t num_valid_params = MAX_NUM_PARAMS; ///< NOSAVE: Number of valid parameters (action 0x14)
@@ -205,7 +206,7 @@ enum FindGRFConfigMode : uint8_t {
 	FGCM_EXACT,       ///< Only find Grfs matching md5sum
 	FGCM_COMPATIBLE,  ///< Find best compatible Grf wrt. desired_version
 	FGCM_NEWEST,      ///< Find newest Grf
-	FGCM_NEWEST_VALID,///< Find newest Grf, ignoring Grfs with GCF_INVALID set
+	FGCM_NEWEST_VALID,///< Find newest Grf, ignoring Grfs with GRFConfigFlag::Invalid set
 	FGCM_ANY,         ///< Use first found
 };
 
diff --git a/src/newgrf_gui.cpp b/src/newgrf_gui.cpp
index b3691415cc..219778b99d 100644
--- a/src/newgrf_gui.cpp
+++ b/src/newgrf_gui.cpp
@@ -128,8 +128,8 @@ static void ShowNewGRFInfo(const GRFConfig &c, const Rect &r, bool show_params)
 	/* Show flags */
 	if (c.status == GCS_NOT_FOUND)       tr.top = DrawStringMultiLine(tr, STR_NEWGRF_SETTINGS_NOT_FOUND);
 	if (c.status == GCS_DISABLED)        tr.top = DrawStringMultiLine(tr, STR_NEWGRF_SETTINGS_DISABLED);
-	if (HasBit(c.flags, GCF_INVALID))    tr.top = DrawStringMultiLine(tr, STR_NEWGRF_SETTINGS_INCOMPATIBLE);
-	if (HasBit(c.flags, GCF_COMPATIBLE)) tr.top = DrawStringMultiLine(tr, STR_NEWGRF_COMPATIBLE_LOADED);
+	if (c.flags.Test(GRFConfigFlag::Invalid))    tr.top = DrawStringMultiLine(tr, STR_NEWGRF_SETTINGS_INCOMPATIBLE);
+	if (c.flags.Test(GRFConfigFlag::Compatible)) tr.top = DrawStringMultiLine(tr, STR_NEWGRF_COMPATIBLE_LOADED);
 
 	/* Draw GRF info if it exists */
 	if (!StrEmpty(c.GetDescription())) {
@@ -834,9 +834,9 @@ struct NewGRFWindow : public Window, NewGRFScanCallback {
 
 		/* Do not show a "not-failure" colour when it actually failed to load */
 		if (pal != PALETTE_TO_RED) {
-			if (HasBit(c.flags, GCF_STATIC)) {
+			if (c.flags.Test(GRFConfigFlag::Static)) {
 				pal = PALETTE_TO_GREY;
-			} else if (HasBit(c.flags, GCF_COMPATIBLE)) {
+			} else if (c.flags.Test(GRFConfigFlag::Compatible)) {
 				pal = PALETTE_TO_ORANGE;
 			}
 		}
@@ -1081,7 +1081,7 @@ struct NewGRFWindow : public Window, NewGRFScanCallback {
 				}
 				this->InvalidateData();
 				if (click_count == 1) {
-					if (this->editable && this->avail_sel != nullptr && !HasBit(this->avail_sel->flags, GCF_INVALID)) SetObjectToPlaceWnd(SPR_CURSOR_MOUSE, PAL_NONE, HT_DRAG, this);
+					if (this->editable && this->avail_sel != nullptr && !this->avail_sel->flags.Test(GRFConfigFlag::Invalid)) SetObjectToPlaceWnd(SPR_CURSOR_MOUSE, PAL_NONE, HT_DRAG, this);
 					break;
 				}
 				/* With double click, continue */
@@ -1089,7 +1089,7 @@ struct NewGRFWindow : public Window, NewGRFScanCallback {
 			}
 
 			case WID_NS_ADD:
-				if (this->avail_sel == nullptr || !this->editable || HasBit(this->avail_sel->flags, GCF_INVALID)) break;
+				if (this->avail_sel == nullptr || !this->editable || this->avail_sel->flags.Test(GRFConfigFlag::Invalid)) break;
 
 				this->AddGRFToActive();
 				break;
@@ -1221,11 +1221,11 @@ struct NewGRFWindow : public Window, NewGRFScanCallback {
 			case GOID_NEWGRF_RESCANNED:
 				/* Search the list for items that are now found and mark them as such. */
 				for (auto &c : this->actives) {
-					bool compatible = HasBit(c->flags, GCF_COMPATIBLE);
+					bool compatible = c->flags.Test(GRFConfigFlag::Compatible);
 					if (c->status != GCS_NOT_FOUND && !compatible) continue;
 
 					const GRFConfig *f = FindGRFConfig(c->ident.grfid, FGCM_EXACT, compatible ? &c->original_md5sum : &c->ident.md5sum);
-					if (f == nullptr || HasBit(f->flags, GCF_INVALID)) continue;
+					if (f == nullptr || f->flags.Test(GRFConfigFlag::Invalid)) continue;
 
 					c = std::make_unique<GRFConfig>(*f);
 				}
@@ -1263,7 +1263,7 @@ struct NewGRFWindow : public Window, NewGRFScanCallback {
 			WID_NS_PRESET_LIST,
 			WID_NS_TOGGLE_PALETTE
 		);
-		this->SetWidgetDisabledState(WID_NS_ADD, !this->editable || this->avail_sel == nullptr || HasBit(this->avail_sel->flags, GCF_INVALID));
+		this->SetWidgetDisabledState(WID_NS_ADD, !this->editable || this->avail_sel == nullptr || this->avail_sel->flags.Test(GRFConfigFlag::Invalid));
 		this->SetWidgetDisabledState(WID_NS_UPGRADE, !this->editable || this->actives.empty() || !this->CanUpgradeCurrent());
 
 		bool disable_all = this->active_sel == nullptr || !this->editable;
@@ -1296,7 +1296,7 @@ struct NewGRFWindow : public Window, NewGRFScanCallback {
 		bool has_compatible = false;
 		for (const auto &c : this->actives) {
 			has_missing    |= c->status == GCS_NOT_FOUND;
-			has_compatible |= HasBit(c->flags, GCF_COMPATIBLE);
+			has_compatible |= c->flags.Test(GRFConfigFlag::Compatible);
 		}
 		StringID text;
 		StringID tool_tip;
@@ -1443,7 +1443,7 @@ private:
 			if (_settings_client.gui.newgrf_show_old_versions) {
 				this->avails.push_back(c.get());
 			} else {
-				const GRFConfig *best = FindGRFConfig(c->ident.grfid, HasBit(c->flags, GCF_INVALID) ? FGCM_NEWEST : FGCM_NEWEST_VALID);
+				const GRFConfig *best = FindGRFConfig(c->ident.grfid, c->flags.Test(GRFConfigFlag::Invalid) ? FGCM_NEWEST : FGCM_NEWEST_VALID);
 				/* Never triggers; FindGRFConfig returns either c, or a newer version of c. */
 				assert(best != nullptr);
 
@@ -1481,12 +1481,12 @@ private:
 	 */
 	bool AddGRFToActive(int ins_pos = -1)
 	{
-		if (this->avail_sel == nullptr || !this->editable || HasBit(this->avail_sel->flags, GCF_INVALID)) return false;
+		if (this->avail_sel == nullptr || !this->editable || this->avail_sel->flags.Test(GRFConfigFlag::Invalid)) return false;
 
 		CloseWindowByClass(WC_TEXTFILE);
 
 		/* Get number of non-static NewGRFs. */
-		size_t count = std::ranges::count_if(this->actives, [](const auto &gc) { return !HasBit(gc->flags, GCF_STATIC); });
+		size_t count = std::ranges::count_if(this->actives, [](const auto &gc) { return !gc->flags.Test(GRFConfigFlag::Static); });
 		if (count >= NETWORK_MAX_GRF_COUNT) {
 			ShowErrorMessage(STR_NEWGRF_TOO_MANY_NEWGRFS, INVALID_STRING_ID, WL_INFO);
 			return false;
@@ -1527,14 +1527,14 @@ void ShowMissingContentWindow(const GRFConfigList &list)
 	/* Only show the things in the current list, or everything when nothing's selected */
 	ContentVector cv;
 	for (const auto &c : list) {
-		if (c->status != GCS_NOT_FOUND && !HasBit(c->flags, GCF_COMPATIBLE)) continue;
+		if (c->status != GCS_NOT_FOUND && !c->flags.Test(GRFConfigFlag::Compatible)) continue;
 
 		ContentInfo *ci = new ContentInfo();
 		ci->type = CONTENT_TYPE_NEWGRF;
 		ci->state = ContentInfo::DOES_NOT_EXIST;
 		ci->name = c->GetName();
 		ci->unique_id = std::byteswap(c->ident.grfid);
-		ci->md5sum = HasBit(c->flags, GCF_COMPATIBLE) ? c->original_md5sum : c->ident.md5sum;
+		ci->md5sum = c->flags.Test(GRFConfigFlag::Compatible) ? c->original_md5sum : c->ident.md5sum;
 		cv.push_back(ci);
 	}
 	ShowNetworkContentListWindow(cv.empty() ? nullptr : &cv, CONTENT_TYPE_NEWGRF);
diff --git a/src/openttd.cpp b/src/openttd.cpp
index 03ad68ba49..28c6f84b3b 100644
--- a/src/openttd.cpp
+++ b/src/openttd.cpp
@@ -244,7 +244,7 @@ static void WriteSavegameInfo(const std::string &name)
 	if (_load_check_data.HasNewGrfs()) {
 		for (const auto &c : _load_check_data.grfconfig) {
 			fmt::format_to(std::back_inserter(message), "{:08X} {} {}\n", std::byteswap(c->ident.grfid),
-				FormatArrayAsHex(HasBit(c->flags, GCF_COMPATIBLE) ? c->original_md5sum : c->ident.md5sum), c->filename);
+				FormatArrayAsHex(c->flags.Test(GRFConfigFlag::Compatible) ? c->original_md5sum : c->ident.md5sum), c->filename);
 		}
 	}
 
diff --git a/src/saveload/afterload.cpp b/src/saveload/afterload.cpp
index cfceb63a23..ed6a91a2e1 100644
--- a/src/saveload/afterload.cpp
+++ b/src/saveload/afterload.cpp
@@ -369,7 +369,7 @@ static void CDECL HandleSavegameLoadCrash(int signum)
 	message.reserve(1024);
 	message += "Loading your savegame caused OpenTTD to crash.\n";
 
-	_saveload_crash_with_missing_newgrfs = std::ranges::any_of(_grfconfig, [](const auto &c) { return HasBit(c->flags, GCF_COMPATIBLE) || c->status == GCS_NOT_FOUND; });
+	_saveload_crash_with_missing_newgrfs = std::ranges::any_of(_grfconfig, [](const auto &c) { return c->flags.Test(GRFConfigFlag::Compatible) || c->status == GCS_NOT_FOUND; });
 
 	if (_saveload_crash_with_missing_newgrfs) {
 		message +=
@@ -386,7 +386,7 @@ static void CDECL HandleSavegameLoadCrash(int signum)
 			"The missing/compatible NewGRFs are:\n";
 
 		for (const auto &c : _grfconfig) {
-			if (HasBit(c->flags, GCF_COMPATIBLE)) {
+			if (c->flags.Test(GRFConfigFlag::Compatible)) {
 				const GRFIdentifier &replaced = _gamelog.GetOverriddenIdentifier(*c);
 				fmt::format_to(std::back_inserter(message), "NewGRF {:08X} (checksum {}) not found.\n  Loaded NewGRF \"{}\" (checksum {}) with same GRF ID instead.\n",
 						std::byteswap(c->ident.grfid), FormatArrayAsHex(c->original_md5sum), c->filename, FormatArrayAsHex(replaced.md5sum));
@@ -708,7 +708,7 @@ bool AfterLoadGame()
 	for (const auto &c : _grfconfig) {
 		if (c->status == GCS_NOT_FOUND) {
 			_gamelog.GRFRemove(c->ident.grfid);
-		} else if (HasBit(c->flags, GCF_COMPATIBLE)) {
+		} else if (c->flags.Test(GRFConfigFlag::Compatible)) {
 			_gamelog.GRFCompatible(c->ident);
 		}
 	}
diff --git a/src/saveload/newgrf_sl.cpp b/src/saveload/newgrf_sl.cpp
index 6de82bb511..41501260fa 100644
--- a/src/saveload/newgrf_sl.cpp
+++ b/src/saveload/newgrf_sl.cpp
@@ -92,7 +92,7 @@ struct NGRFChunkHandler : ChunkHandler {
 		int index = 0;
 
 		for (const auto &c : _grfconfig) {
-			if (HasBit(c->flags, GCF_STATIC) || HasBit(c->flags, GCF_INIT_ONLY)) continue;
+			if (c->flags.Any({GRFConfigFlag::Static, GRFConfigFlag::InitOnly})) continue;
 			this->SaveParameters(*c);
 			SlSetArrayIndex(index++);
 			SlObject(c.get(), description);
diff --git a/src/script/api/script_newgrf.cpp b/src/script/api/script_newgrf.cpp
index e04b7a6b4e..5e0da50269 100644
--- a/src/script/api/script_newgrf.cpp
+++ b/src/script/api/script_newgrf.cpp
@@ -18,7 +18,7 @@
 ScriptNewGRFList::ScriptNewGRFList()
 {
 	for (const auto &c : _grfconfig) {
-		if (!HasBit(c->flags, GCF_STATIC)) {
+		if (!c->flags.Test(GRFConfigFlag::Static)) {
 			this->AddItem(std::byteswap(c->ident.grfid));
 		}
 	}
@@ -28,14 +28,14 @@ ScriptNewGRFList::ScriptNewGRFList()
 {
 	grfid = std::byteswap(GB(grfid, 0, 32)); // Match people's expectations.
 
-	return std::ranges::any_of(_grfconfig, [grfid](const auto &c) { return !HasBit(c->flags, GCF_STATIC) && c->ident.grfid == grfid; });
+	return std::ranges::any_of(_grfconfig, [grfid](const auto &c) { return !c->flags.Test(GRFConfigFlag::Static) && c->ident.grfid == grfid; });
 }
 
 /* static */ SQInteger ScriptNewGRF::GetVersion(SQInteger grfid)
 {
 	grfid = std::byteswap(GB(grfid, 0, 32)); // Match people's expectations.
 
-	auto it = std::ranges::find_if(_grfconfig, [grfid](const auto &c) { return !HasBit(c->flags, GCF_STATIC) && c->ident.grfid == grfid; });
+	auto it = std::ranges::find_if(_grfconfig, [grfid](const auto &c) { return !c->flags.Test(GRFConfigFlag::Static) && c->ident.grfid == grfid; });
 	if (it != std::end(_grfconfig)) return (*it)->version;
 
 	return 0;
@@ -45,7 +45,7 @@ ScriptNewGRFList::ScriptNewGRFList()
 {
 	grfid = std::byteswap(GB(grfid, 0, 32)); // Match people's expectations.
 
-	auto it = std::ranges::find_if(_grfconfig, [grfid](const auto &c) { return !HasBit(c->flags, GCF_STATIC) && c->ident.grfid == grfid; });
+	auto it = std::ranges::find_if(_grfconfig, [grfid](const auto &c) { return !c->flags.Test(GRFConfigFlag::Static) && c->ident.grfid == grfid; });
 	if (it != std::end(_grfconfig)) return (*it)->GetName();
 
 	return std::nullopt;
diff --git a/src/settings.cpp b/src/settings.cpp
index 54c97be84a..77da07233b 100644
--- a/src/settings.cpp
+++ b/src/settings.cpp
@@ -1107,14 +1107,14 @@ static GRFConfigList GRFLoadConfig(const IniFile &ini, const char *grpname, bool
 		}
 
 		/* Check if item is valid */
-		if (!FillGRFDetails(*c, is_static) || HasBit(c->flags, GCF_INVALID)) {
+		if (!FillGRFDetails(*c, is_static) || c->flags.Test(GRFConfigFlag::Invalid)) {
 			if (c->status == GCS_NOT_FOUND) {
 				SetDParam(1, STR_CONFIG_ERROR_INVALID_GRF_NOT_FOUND);
-			} else if (HasBit(c->flags, GCF_UNSAFE)) {
+			} else if (c->flags.Test(GRFConfigFlag::Unsafe)) {
 				SetDParam(1, STR_CONFIG_ERROR_INVALID_GRF_UNSAFE);
-			} else if (HasBit(c->flags, GCF_SYSTEM)) {
+			} else if (c->flags.Test(GRFConfigFlag::System)) {
 				SetDParam(1, STR_CONFIG_ERROR_INVALID_GRF_SYSTEM);
-			} else if (HasBit(c->flags, GCF_INVALID)) {
+			} else if (c->flags.Test(GRFConfigFlag::Invalid)) {
 				SetDParam(1, STR_CONFIG_ERROR_INVALID_GRF_INCOMPATIBLE);
 			} else {
 				SetDParam(1, STR_CONFIG_ERROR_INVALID_GRF_UNKNOWN);
@@ -1136,7 +1136,7 @@ static GRFConfigList GRFLoadConfig(const IniFile &ini, const char *grpname, bool
 
 		if (is_static) {
 			/* Mark file as static to avoid saving in savegame. */
-			SetBit(c->flags, GCF_STATIC);
+			c->flags.Set(GRFConfigFlag::Static);
 		} else if (++num_grfs > NETWORK_MAX_GRF_COUNT) {
 			/* Check we will not load more non-static NewGRFs than allowed. This could trigger issues for game servers. */
 			ShowErrorMessage(STR_CONFIG_ERROR, STR_NEWGRF_ERROR_TOO_MANY_NEWGRFS_LOADED, WL_CRITICAL);
diff --git a/src/survey.cpp b/src/survey.cpp
index 313606361b..a4140dbdca 100644
--- a/src/survey.cpp
+++ b/src/survey.cpp
@@ -369,7 +369,7 @@ void SurveyGrfs(nlohmann::json &survey)
 		if ((c->palette & GRFP_BLT_MASK) == GRFP_BLT_UNSET) grf["blitter"] = "unset";
 		if ((c->palette & GRFP_BLT_MASK) == GRFP_BLT_32BPP) grf["blitter"] = "32bpp";
 
-		grf["is_static"] = HasBit(c->flags, GCF_STATIC);
+		grf["is_static"] = c->flags.Test(GRFConfigFlag::Static);
 		grf["parameters"] = std::span<const uint32_t>(c->param);
 	}
 }