diff --git a/src/image.cpp b/src/image.cpp
index 3749297..bfb0466 100644
--- a/src/image.cpp
+++ b/src/image.cpp
@@ -3315,6 +3315,7 @@ namespace bimg
 		HashWriter(bx::WriterI* _writer)
 			: m_writer(_writer)
 		{
+			begin();
 		}
 
 		void begin()
@@ -3342,34 +3343,28 @@ namespace bimg
 	{
 		BX_ERROR_SCOPE(_err);
 
-		HashWriter<bx::HashCrc32> writer(_writer);
-
 		int32_t total = 0;
-		total += bx::write(&writer, "\x89PNG\r\n\x1a\n", _err);
+		total += bx::write(_writer, "\x89PNG\r\n\x1a\n", _err);
+		total += bx::write(_writer, bx::toBigEndian<uint32_t>(13), _err);
 
-		total += bx::write(&writer, bx::toBigEndian<uint32_t>(13), _err);
-		writer.begin();
-		total += bx::write(&writer, "IHDR", _err);
-		total += bx::write(&writer, bx::toBigEndian(_width),  _err);
-		total += bx::write(&writer, bx::toBigEndian(_height), _err);
-		total += bx::write(&writer, "\x08\x06", _err);
-		total += bx::writeRep(&writer, 0, 3, _err);
-		total += bx::write(&writer, bx::toBigEndian(writer.end() ), _err);
+		HashWriter<bx::HashCrc32> writerC(_writer);
+		total += bx::write(&writerC, "IHDR", _err);
+		total += bx::write(&writerC, bx::toBigEndian(_width),  _err);
+		total += bx::write(&writerC, bx::toBigEndian(_height), _err);
+		total += bx::write(&writerC, "\x08\x06", _err);
+		total += bx::writeRep(&writerC, 0, 3, _err);
+		total += bx::write(_writer, bx::toBigEndian(writerC.end() ), _err);
 
-		const uint8_t* src = (const uint8_t*)_src;
-		const uint32_t bpp = _grayscale ? 8 : 32;
+		const uint32_t bpp    = _grayscale ? 8 : 32;
 		const uint32_t stride = _width*bpp/8;
 		const uint16_t zlen   = bx::toLittleEndian<uint16_t>(uint16_t(stride + 1) );
 		const uint16_t zlenC  = bx::toLittleEndian<uint16_t>(~zlen);
 
-		total += bx::write(&writer, bx::toBigEndian<uint32_t>(_height*(stride+6)+6), _err);
+		total += bx::write(_writer, bx::toBigEndian<uint32_t>(_height*(stride+6)+6), _err);
 
-		writer.begin();
-		total += bx::write(&writer, "IDAT", _err);
-		total += bx::write(&writer, "\x78\x9c", _err);
-
-		bx::HashAdler32 chksum;
-		chksum.begin();
+		writerC.begin();
+		total += bx::write(&writerC, "IDAT", _err);
+		total += bx::write(&writerC, "\x78\x9c", _err);
 
 		const uint8_t* data = (const uint8_t*)_src;
 		int32_t step = int32_t(_srcPitch);
@@ -3379,21 +3374,19 @@ namespace bimg
 			step = -step;
 		}
 
+		HashWriter<bx::HashAdler32> writerA(&writerC);
+
 		for (uint32_t ii = 0; ii < _height && _err->isOk(); ++ii)
 		{
-			chksum.add(0);
-			chksum.add(&src[ii*_srcPitch], stride);
+			total += bx::write(&writerC, uint8_t(ii == _height-1 ? 1 : 0), _err);
+			total += bx::write(&writerC, zlen,  _err);
+			total += bx::write(&writerC, zlenC, _err);
 
-			total += bx::write(&writer, uint8_t(ii == _height-1 ? 1 : 0), _err);
-
-			total += bx::write(&writer, zlen,  _err);
-			total += bx::write(&writer, zlenC, _err);
-
-			total += bx::write(&writer, uint8_t(0), _err);
+			total += bx::write(&writerA, uint8_t(0), _err);
 
 			if (_grayscale)
 			{
-				total += bx::write(&writer, data, stride, _err);
+				total += bx::write(&writerA, data, stride, _err);
 			}
 			else
 			{
@@ -3404,22 +3397,22 @@ namespace bimg
 					const uint8_t gg = bgra[1];
 					const uint8_t rr = bgra[2];
 					const uint8_t aa = bgra[3];
-					total += bx::write(&writer, rr, _err);
-					total += bx::write(&writer, gg, _err);
-					total += bx::write(&writer, bb, _err);
-					total += bx::write(&writer, aa, _err);
+					total += bx::write(&writerA, rr, _err);
+					total += bx::write(&writerA, gg, _err);
+					total += bx::write(&writerA, bb, _err);
+					total += bx::write(&writerA, aa, _err);
 				}
 			}
 
 			data += step;
 		}
-		total += bx::write(&writer, bx::toBigEndian(chksum.end() ), _err);
-		total += bx::write(&writer, bx::toBigEndian(writer.end() ), _err);
+		total += bx::write(&writerC, bx::toBigEndian(writerA.end() ), _err);
+		total += bx::write(_writer,  bx::toBigEndian(writerC.end() ), _err);
 
-		writer.begin();
-		total += bx::write(&writer, uint32_t(0), _err);
-		total += bx::write(&writer, "IEND", _err);
-		total += bx::write(&writer, bx::toBigEndian(writer.end() ), _err);
+		writerC.begin();
+		total += bx::write(&writerC, uint32_t(0), _err);
+		total += bx::write(&writerC, "IEND", _err);
+		total += bx::write(_writer,  bx::toBigEndian(writerC.end() ), _err);
 
 		return total;
 	}