diff --git a/src/settings.cpp b/src/settings.cpp
index ab83152592..394530f758 100644
--- a/src/settings.cpp
+++ b/src/settings.cpp
@@ -3897,9 +3897,9 @@ static void Check_PATX()
 }
 
 static const ChunkHandler setting_chunk_handlers[] = {
-	{ 'OPTS', nullptr,   Load_OPTS, nullptr, nullptr,    CH_RIFF },
+	{ 'OPTS', nullptr,   Load_OPTS, nullptr, nullptr,    CH_READONLY },
 	MakeSaveUpstreamFeatureConditionalLoadUpstreamChunkHandler<'PATS', XSLFI_TABLE_PATS>(Load_PATS, nullptr, Check_PATS),
-	{ 'PATX', nullptr,   Load_PATX, nullptr, Check_PATX, CH_RIFF },
+	{ 'PATX', nullptr,   Load_PATX, nullptr, Check_PATX, CH_READONLY },
 };
 
 extern const ChunkHandlerTable _setting_chunk_handlers(setting_chunk_handlers);
diff --git a/src/sl/engine_sl.cpp b/src/sl/engine_sl.cpp
index a86f6a9f6f..9787974274 100644
--- a/src/sl/engine_sl.cpp
+++ b/src/sl/engine_sl.cpp
@@ -117,7 +117,7 @@ void AfterLoadEngines()
 static const ChunkHandler engine_chunk_handlers[] = {
 	MakeUpstreamChunkHandler<'EIDS', GeneralUpstreamChunkLoadInfo>(),
 	MakeUpstreamChunkHandler<'ENGN', GeneralUpstreamChunkLoadInfo>(),
-	{ 'ENGS', nullptr,   Load_ENGS, nullptr, nullptr, CH_RIFF  },
+	{ 'ENGS', nullptr,   Load_ENGS, nullptr, nullptr, CH_READONLY  },
 };
 
 extern const ChunkHandlerTable _engine_chunk_handlers(engine_chunk_handlers);
diff --git a/src/sl/station_sl.cpp b/src/sl/station_sl.cpp
index 1555acdb6e..2177359f88 100644
--- a/src/sl/station_sl.cpp
+++ b/src/sl/station_sl.cpp
@@ -859,7 +859,7 @@ static void Load_DOCK()
 }
 
 static const ChunkHandler station_chunk_handlers[] = {
-	{ 'STNS', nullptr,       Load_STNS,     Ptrs_STNS,     nullptr, CH_ARRAY },
+	{ 'STNS', nullptr,       Load_STNS,     Ptrs_STNS,     nullptr, CH_READONLY },
 	{ 'STNN', Save_STNN,     Load_STNN,     Ptrs_STNN,     nullptr, CH_ARRAY },
 	{ 'ROAD', Save_ROADSTOP, Load_ROADSTOP, Ptrs_ROADSTOP, nullptr, CH_ARRAY },
 	{ 'DOCK', nullptr,       Load_DOCK,     nullptr,       nullptr, CH_READONLY },