diff --git a/src/nostalgia/core/CMakeLists.txt b/src/nostalgia/core/CMakeLists.txt
index c2b94caf..96d28345 100644
--- a/src/nostalgia/core/CMakeLists.txt
+++ b/src/nostalgia/core/CMakeLists.txt
@@ -5,6 +5,8 @@ add_library(
 		media.cpp
 )
 
+target_compile_options(NostalgiaCore PRIVATE -Wsign-conversion)
+
 target_link_libraries(
 	NostalgiaCore PUBLIC
 		OxFS
diff --git a/src/nostalgia/core/gfx.cpp b/src/nostalgia/core/gfx.cpp
index 68d7f6e6..617ead0a 100644
--- a/src/nostalgia/core/gfx.cpp
+++ b/src/nostalgia/core/gfx.cpp
@@ -142,9 +142,9 @@ static char charMap[128] = {
 };
 
 Color32 toColor32(Color16 nc) noexcept {
-	Color32 r = ((nc & 0b0000000000011111) >> 0) * 8;
-	Color32 g = ((nc & 0b0000001111100000) >> 5) * 8;
-	Color32 b = ((nc & 0b0111110000000000) >> 10) * 8;
+	Color32 r = static_cast<Color32>(((nc & 0b0000000000011111) >> 0) * 8);
+	Color32 g = static_cast<Color32>(((nc & 0b0000001111100000) >> 5) * 8);
+	Color32 b = static_cast<Color32>(((nc & 0b0111110000000000) >> 10) * 8);
 	Color32 a = 255;
 	return a | (b << 8) | (g << 16) | (r << 24);
 }
@@ -177,7 +177,7 @@ uint8_t blue32(Color16 c) noexcept {
 
 void puts(Context *ctx, int column, int row, const char *str) {
 	for (int i = 0; str[i]; i++) {
-		setTile(ctx, 0, column + i, row, charMap[static_cast<int>(str[i])]);
+		setTile(ctx, 0, column + i, row, static_cast<uint8_t>(charMap[static_cast<int>(str[i])]));
 	}
 }
 
diff --git a/src/nostalgia/core/sdl/gfx.cpp b/src/nostalgia/core/sdl/gfx.cpp
index fc301754..e563dff0 100644
--- a/src/nostalgia/core/sdl/gfx.cpp
+++ b/src/nostalgia/core/sdl/gfx.cpp
@@ -27,7 +27,7 @@ struct SdlImplData {
 	SDL_Renderer *renderer = nullptr;
 	std::array<SDL_Texture*, 4> bgTextures;
 	std::array<TileMap, 4> bgTileMaps;
-	uint64_t prevFpsCheckTime = 0;
+	int64_t prevFpsCheckTime = 0;
 	uint64_t draws = 0;
 };
 
@@ -105,7 +105,7 @@ ox::Error loadTileSheet(Context *ctx,
 	}
 	oxReturnError(readMC<NostalgiaPalette>(ctx, palettePath).get(&palette));
 
-	const auto bytesPerTile = tilesheet.bpp == 8 ? 64 : 32;
+	const unsigned bytesPerTile = tilesheet.bpp == 8 ? 64 : 32;
 	const auto tiles = tilesheet.tiles.size() / bytesPerTile;
 	const int width = 8;
 	const int height = 8 * tiles;
@@ -126,11 +126,12 @@ ox::Error loadTileSheet(Context *ctx,
 	SDL_FreeSurface(surface);
 	SDL_FreePalette(sdlPalette);
 
+	auto sectionIdx = static_cast<unsigned>(section);
 	if (tss == TileSheetSpace::Background) {
-		if (id->bgTextures[section]) {
-			SDL_DestroyTexture(id->bgTextures[section]);
+		if (id->bgTextures[sectionIdx]) {
+			SDL_DestroyTexture(id->bgTextures[sectionIdx]);
 		}
-		id->bgTextures[section] = texture;
+		id->bgTextures[sectionIdx] = texture;
 	}
 
 	return OxError(0);