diff --git a/src/gfx/png.cpp b/src/gfx/png.cpp
index b9b8e815..a48c3c28 100644
--- a/src/gfx/png.cpp
+++ b/src/gfx/png.cpp
@@ -100,7 +100,8 @@ Png::Png(char const *filename, std::streambuf &file) {
 	    png, info, &width, &height, &bitDepth, &colorType, &interlaceType, nullptr, nullptr
 	);
 
-	pixels.resize(static_cast<size_t>(width) * static_cast<size_t>(height));
+	size_t nbPixels = static_cast<size_t>(width) * static_cast<size_t>(height);
+	pixels.resize(nbPixels);
 
 	auto colorTypeName = [](int type) {
 		switch (type) {
@@ -212,7 +213,7 @@ Png::Png(char const *filename, std::streambuf &file) {
 	assume(png_get_bit_depth(png, info) == 8);
 
 	// Now that metadata has been read, we can read the image data
-	std::vector<png_byte> image(width * height * 4);
+	std::vector<png_byte> image(nbPixels * 4);
 	std::vector<png_bytep> rowPtrs(height);
 	for (uint32_t y = 0; y < height; ++y) {
 		rowPtrs[y] = image.data() + y * width * 4;
diff --git a/src/gfx/process.cpp b/src/gfx/process.cpp
index 6af0203e..82ac0778 100644
--- a/src/gfx/process.cpp
+++ b/src/gfx/process.cpp
@@ -1146,10 +1146,10 @@ continue_visiting_tiles:;
 		uint32_t const nbTilesH = image.png.height / 8, nbTilesW = image.png.width / 8;
 
 		// Check the tile count
-		if (uint32_t nbTiles = nbTilesW * nbTilesH;
+		if (uint64_t nbTiles = nbTilesW * nbTilesH;
 		    nbTiles > options.maxNbTiles[0] + options.maxNbTiles[1]) {
 			fatal(
-			    "Image contains %" PRIu32 " tiles, exceeding the limit of %" PRIu16 " + %" PRIu16,
+			    "Image contains %" PRIu64 " tiles, exceeding the limit of %" PRIu16 " + %" PRIu16,
 			    nbTiles,
 			    options.maxNbTiles[0],
 			    options.maxNbTiles[1]