diff --git a/src/nostalgia/modules/core/include/nostalgia/core/tilesheet.hpp b/src/nostalgia/modules/core/include/nostalgia/core/tilesheet.hpp
index dfbe0303..9821cc46 100644
--- a/src/nostalgia/modules/core/include/nostalgia/core/tilesheet.hpp
+++ b/src/nostalgia/modules/core/include/nostalgia/core/tilesheet.hpp
@@ -33,7 +33,14 @@ struct TileSheetV1 {
 
 [[nodiscard]]
 constexpr bool valid(TileSheetV1 const&ts) noexcept {
-	return ts.bpp == 4 || ts.bpp == 8;
+	auto const bytes = static_cast<size_t>(ts.columns * ts.rows * PixelsPerTile) / (ts.bpp == 4 ? 2 : 1);
+	return (ts.bpp == 4 || ts.bpp == 8) && ts.pixels.size() == bytes;
+}
+
+constexpr ox::Error repair(TileSheetV1 &ts, int bpp) noexcept {
+	auto const bytes = static_cast<size_t>(ts.columns * ts.rows * PixelsPerTile) / (bpp == 4 ? 2 : 1);
+	ts.pixels.resize(bytes);
+	return {};
 }
 
 
@@ -65,9 +72,34 @@ struct TileSheetV2 {
 
 };
 
+[[nodiscard]]
+constexpr bool valid(TileSheetV2::SubSheet const&ss, int bpp) noexcept {
+	auto const bytes = static_cast<size_t>(ss.columns * ss.rows * PixelsPerTile) / (bpp == 4 ? 2 : 1);
+	return ox::all_of(ss.subsheets.begin(), ss.subsheets.end(),
+			[bpp, bytes](TileSheetV2::SubSheet const&s) {
+		return bytes == s.pixels.size() && valid(s, bpp);
+	});
+}
+
 [[nodiscard]]
 constexpr bool valid(TileSheetV2 const&ts) noexcept {
-	return ts.bpp == 4 || ts.bpp == 8;
+	return (ts.bpp == 4 || ts.bpp == 8) && valid(ts.subsheet, ts.bpp);
+}
+
+constexpr void repair(TileSheetV2::SubSheet &ss, int bpp) noexcept {
+	auto const bytes = static_cast<size_t>(ss.columns * ss.rows * PixelsPerTile) / (bpp == 4 ? 2 : 1);
+	ss.pixels.resize(bytes);
+	for (auto &s : ss.subsheets) {
+		repair(s, bpp);
+	}
+}
+
+constexpr ox::Error repair(TileSheetV2 &ts) noexcept {
+	if (ts.bpp != 4 && ts.bpp != 8) {
+		return OxError(1, "Unable to repair TileSheet");
+	}
+	repair(ts.subsheet, ts.bpp);
+	return {};
 }
 
 
@@ -110,9 +142,34 @@ struct TileSheetV3 {
 
 };
 
+[[nodiscard]]
+constexpr bool valid(TileSheetV3::SubSheet const&ss, int bpp) noexcept {
+	auto const bytes = static_cast<size_t>(ss.columns * ss.rows * PixelsPerTile) / (bpp == 4 ? 2 : 1);
+	return ox::all_of(ss.subsheets.begin(), ss.subsheets.end(),
+			[bpp, bytes](TileSheetV3::SubSheet const&s) {
+		return bytes == s.pixels.size() && valid(s, bpp);
+	});
+}
+
 [[nodiscard]]
 constexpr bool valid(TileSheetV3 const&ts) noexcept {
-	return ts.bpp == 4 || ts.bpp == 8;
+	return (ts.bpp == 4 || ts.bpp == 8) && valid(ts.subsheet, ts.bpp);
+}
+
+constexpr void repair(TileSheetV3::SubSheet &ss, int bpp) noexcept {
+	auto const bytes = static_cast<size_t>(ss.columns * ss.rows * PixelsPerTile) / (bpp == 4 ? 2 : 1);
+	ss.pixels.resize(bytes);
+	for (auto &s : ss.subsheets) {
+		repair(s, bpp);
+	}
+}
+
+constexpr ox::Error repair(TileSheetV3 &ts) noexcept {
+	if (ts.bpp != 4 && ts.bpp != 8) {
+		return OxError(1, "Unable to repair TileSheet");
+	}
+	repair(ts.subsheet, ts.bpp);
+	return {};
 }
 
 
@@ -173,9 +230,34 @@ struct TileSheetV4 {
 
 };
 
+[[nodiscard]]
+constexpr bool valid(TileSheetV4::SubSheet const&ss, int bpp) noexcept {
+	auto const bytes = static_cast<size_t>(ss.columns * ss.rows * PixelsPerTile) / (bpp == 4 ? 2 : 1);
+	return ox::all_of(ss.subsheets.begin(), ss.subsheets.end(),
+			[bpp, bytes](TileSheetV4::SubSheet const&s) {
+		return bytes == s.pixels.size() && valid(s, bpp);
+	});
+}
+
 [[nodiscard]]
 constexpr bool valid(TileSheetV4 const&ts) noexcept {
-	return ts.bpp == 4 || ts.bpp == 8;
+	return (ts.bpp == 4 || ts.bpp == 8) && valid(ts.subsheet, ts.bpp);
+}
+
+constexpr void repair(TileSheetV4::SubSheet &ss, int bpp) noexcept {
+	auto const bytes = static_cast<size_t>(ss.columns * ss.rows * PixelsPerTile) / (bpp == 4 ? 2 : 1);
+	ss.pixels.resize(bytes);
+	for (auto &s : ss.subsheets) {
+		repair(s, bpp);
+	}
+}
+
+constexpr ox::Error repair(TileSheetV4 &ts) noexcept {
+	if (ts.bpp != 4 && ts.bpp != 8) {
+		return OxError(1, "Unable to repair TileSheet");
+	}
+	repair(ts.subsheet, ts.bpp);
+	return {};
 }