diff --git a/app/exiv2.cpp b/app/exiv2.cpp
index 4421c29f..18654f3b 100644
--- a/app/exiv2.cpp
+++ b/app/exiv2.cpp
@@ -937,10 +937,10 @@ int Params::nonoption(const std::string& argv) {
   return rc;
 }  // Params::nonoption
 
-static int readFileToBuf(FILE* f, Exiv2::DataBuf& buf) {
+static size_t readFileToBuf(FILE* f, Exiv2::DataBuf& buf) {
   const int buff_size = 4 * 1028;
   std::vector<Exiv2::byte> bytes(buff_size);
-  int nBytes = 0;
+  size_t nBytes = 0;
   bool more{true};
   std::array<char, buff_size> buff;
   while (more) {
diff --git a/include/exiv2/webpimage.hpp b/include/exiv2/webpimage.hpp
index 2d56706c..6b84d939 100644
--- a/include/exiv2/webpimage.hpp
+++ b/include/exiv2/webpimage.hpp
@@ -64,7 +64,7 @@ class EXIV2API WebPImage : public Image {
   void doWriteMetadata(BasicIo& outIo);
   //! @name NOT Implemented
   //@{
-  static long getHeaderOffset(const byte* data, long data_size, const byte* header, long header_size);
+  static long getHeaderOffset(const byte* data, size_t data_size, const byte* header, size_t header_size);
   static bool equalsWebPTag(Exiv2::DataBuf& buf, const char* str);
   void debugPrintHex(byte* data, long size);
   void decodeChunks(long filesize);
diff --git a/src/basicio.cpp b/src/basicio.cpp
index 361f52aa..27c3d0ec 100644
--- a/src/basicio.cpp
+++ b/src/basicio.cpp
@@ -728,7 +728,7 @@ void MemIo::transfer(BasicIo& src) {
 }
 
 size_t MemIo::write(BasicIo& src) {
-  if (static_cast<BasicIo*>(this) == &src)
+  if (this == &src)
     return 0;
   if (!src.isopen())
     return 0;
diff --git a/src/bmffimage.cpp b/src/bmffimage.cpp
index a293179c..b71dbad0 100644
--- a/src/bmffimage.cpp
+++ b/src/bmffimage.cpp
@@ -506,7 +506,7 @@ void BmffImage::parseTiff(uint32_t root_tag, uint64_t length) {
   if (length > 8) {
     enforce(length - 8 <= io_->size() - io_->tell(), ErrorCode::kerCorruptedMetadata);
     enforce(length - 8 <= std::numeric_limits<uint64_t>::max(), ErrorCode::kerCorruptedMetadata);
-    DataBuf data(static_cast<size_t>(length) - 8);
+    DataBuf data(static_cast<size_t>(length - 8u));
     const size_t bufRead = io_->read(data.data(), data.size());
 
     if (io_->error())
@@ -514,8 +514,7 @@ void BmffImage::parseTiff(uint32_t root_tag, uint64_t length) {
     if (bufRead != data.size())
       throw Error(ErrorCode::kerInputDataReadFailed);
 
-    Internal::TiffParserWorker::decode(exifData(), iptcData(), xmpData(), data.c_data(),
-                                       static_cast<uint32_t>(data.size()), root_tag,
+    Internal::TiffParserWorker::decode(exifData(), iptcData(), xmpData(), data.c_data(), data.size(), root_tag,
                                        Internal::TiffMapping::findDecoder);
   }
 }
@@ -526,13 +525,12 @@ void BmffImage::parseXmp(uint64_t length, uint64_t start) {
     enforce(length <= io_->size() - start, ErrorCode::kerCorruptedMetadata);
 
     long restore = io_->tell();
-    enforce(start <= std::numeric_limits<uint64_t>::max(), ErrorCode::kerCorruptedMetadata);
     io_->seek(static_cast<long>(start), BasicIo::beg);
 
-    enforce(length < std::numeric_limits<uint64_t>::max(), ErrorCode::kerCorruptedMetadata);
-    DataBuf xmp(static_cast<size_t>(length + 1));
-    xmp.write_uint8(static_cast<size_t>(length), 0);  // ensure xmp is null terminated!
-    if (io_->read(xmp.data(), static_cast<size_t>(length)) != length)
+    size_t lengthSizeT = static_cast<size_t>(length);
+    DataBuf xmp(lengthSizeT + 1);
+    xmp.write_uint8(lengthSizeT, 0);  // ensure xmp is null terminated!
+    if (io_->read(xmp.data(), lengthSizeT) != lengthSizeT)
       throw Error(ErrorCode::kerInputDataReadFailed);
     if (io_->error())
       throw Error(ErrorCode::kerFailedToReadImageData);
@@ -554,7 +552,7 @@ void BmffImage::parseCr3Preview(DataBuf& data, std::ostream& out, bool bTrace, u
   enforce(here >= 0 && here <= std::numeric_limits<long>::max() - static_cast<long>(relative_position),
           ErrorCode::kerCorruptedMetadata);
   NativePreview nativePreview;
-  nativePreview.position_ = here + static_cast<long>(relative_position);
+  nativePreview.position_ = here + relative_position;
   nativePreview.width_ = data.read_uint16(width_offset, endian_);
   nativePreview.height_ = data.read_uint16(height_offset, endian_);
   nativePreview.size_ = data.read_uint32(size_offset, endian_);
diff --git a/src/crwimage_int.cpp b/src/crwimage_int.cpp
index e807f9f9..be229e31 100644
--- a/src/crwimage_int.cpp
+++ b/src/crwimage_int.cpp
@@ -244,7 +244,7 @@ void CiffDirectory::readDirectory(const byte* pData, size_t size, ByteOrder byte
   std::cout << "Directory at offset " << std::dec << o << ", " << count << " entries \n";
 #endif
   o += 2;
-  if (static_cast<uint32_t>(count) * 10 > size - o)
+  if (count * 10u > size - o)
     throw Error(ErrorCode::kerCorruptedMetadata);
 
   for (uint16_t i = 0; i < count; ++i) {
diff --git a/src/image.cpp b/src/image.cpp
index f2d5873e..07a620a7 100644
--- a/src/image.cpp
+++ b/src/image.cpp
@@ -602,7 +602,7 @@ void Image::setComment(std::string_view comment) {
 
 void Image::setIccProfile(Exiv2::DataBuf&& iccProfile, bool bTestValid) {
   if (bTestValid) {
-    if (iccProfile.size() < static_cast<long>(sizeof(long))) {
+    if (iccProfile.size() < sizeof(long)) {
       throw Error(ErrorCode::kerInvalidIccProfile);
     }
     const size_t size = iccProfile.read_uint32(0, bigEndian);
diff --git a/src/mrwimage.cpp b/src/mrwimage.cpp
index aaca5c78..2fc23b42 100644
--- a/src/mrwimage.cpp
+++ b/src/mrwimage.cpp
@@ -106,7 +106,7 @@ void MrwImage::readMetadata() {
   io_->read(buf.data(), buf.size());
   enforce(!io_->error() && !io_->eof(), ErrorCode::kerFailedToReadImageData);
 
-  ByteOrder bo = TiffParser::decode(exifData_, iptcData_, xmpData_, buf.c_data(), static_cast<uint32_t>(buf.size()));
+  ByteOrder bo = TiffParser::decode(exifData_, iptcData_, xmpData_, buf.c_data(), buf.size());
   setByteOrder(bo);
 }  // MrwImage::readMetadata
 
diff --git a/src/pgfimage.cpp b/src/pgfimage.cpp
index dcbfc3d0..7de1aa66 100644
--- a/src/pgfimage.cpp
+++ b/src/pgfimage.cpp
@@ -90,13 +90,13 @@ void PgfImage::readMetadata() {
   // And now, the most interesting, the user data byte array where metadata are stored as small image.
 
   enforce(headerSize <= std::numeric_limits<size_t>::max() - 8, ErrorCode::kerCorruptedMetadata);
-  long size = static_cast<long>(headerSize) + 8 - io_->tell();
+  size_t size = headerSize + 8 - static_cast<size_t>(io_->tell());
 
 #ifdef EXIV2_DEBUG_MESSAGES
   std::cout << "Exiv2::PgfImage::readMetadata: Found Image data (" << size << " bytes)\n";
 #endif
 
-  if (size < 0 || static_cast<size_t>(size) > io_->size())
+  if (size > io_->size())
     throw Error(ErrorCode::kerInputDataReadFailed);
   if (size == 0)
     return;
diff --git a/src/preview.cpp b/src/preview.cpp
index 3333b73b..7a33528b 100644
--- a/src/preview.cpp
+++ b/src/preview.cpp
@@ -31,7 +31,7 @@ bool cmpPreviewProperties(const PreviewProperties &lhs, const PreviewProperties
 }
 
 /// @brief Decode a Hex string.
-DataBuf decodeHex(const byte *src, long srcSize);
+DataBuf decodeHex(const byte *src, size_t srcSize);
 
 /// @brief Decode a Base64 string.
 DataBuf decodeBase64(const std::string &src);
@@ -409,12 +409,12 @@ DataBuf LoaderNative::getData() const {
     return {data + nativePreview_.position_, nativePreview_.size_};
   }
   if (nativePreview_.filter_ == "hex-ai7thumbnail-pnm") {
-    const DataBuf ai7thumbnail = decodeHex(data + nativePreview_.position_, static_cast<long>(nativePreview_.size_));
+    const DataBuf ai7thumbnail = decodeHex(data + nativePreview_.position_, nativePreview_.size_);
     const DataBuf rgb = decodeAi7Thumbnail(ai7thumbnail);
     return makePnm(width_, height_, rgb);
   }
   if (nativePreview_.filter_ == "hex-irb") {
-    const DataBuf psData = decodeHex(data + nativePreview_.position_, static_cast<long>(nativePreview_.size_));
+    const DataBuf psData = decodeHex(data + nativePreview_.position_, nativePreview_.size_);
     const byte *record;
     uint32_t sizeHdr = 0;
     uint32_t sizeData = 0;
@@ -479,7 +479,7 @@ LoaderExifJpeg::LoaderExifJpeg(PreviewId id, const Image &image, int parIdx) : L
     }
   }
 
-  if (Safe::add(offset_, size_) > static_cast<uint32_t>(image_.io().size()))
+  if (Safe::add(offset_, size_) > image_.io().size())
     return;
 
   valid_ = true;
@@ -648,7 +648,7 @@ LoaderTiff::LoaderTiff(PreviewId id, const Image &image, int parIdx) :
   if (offsetCount != pos->value().count())
     return;
   for (size_t i = 0; i < offsetCount; i++) {
-    size_ += pos->toUint32(static_cast<long>(i));
+    size_ += pos->toUint32(i);
   }
 
   if (size_ == 0)
@@ -727,7 +727,7 @@ DataBuf LoaderTiff::getData() const {
           dataValue.setDataArea(base + offset, size);
       } else {
         // FIXME: the buffer is probably copied twice, it should be optimized
-        enforce(size_ <= static_cast<uint32_t>(io.size()), ErrorCode::kerCorruptedMetadata);
+        enforce(size_ <= io.size(), ErrorCode::kerCorruptedMetadata);
         DataBuf buf(size_);
         uint32_t idxBuf = 0;
         for (size_t i = 0; i < sizes.count(); i++) {
@@ -792,7 +792,7 @@ LoaderXmpJpeg::LoaderXmpJpeg(PreviewId id, const Image &image, int parIdx) : Loa
   width_ = widthDatum->toUint32();
   height_ = heightDatum->toUint32();
   preview_ = decodeBase64(imageDatum->toString());
-  size_ = static_cast<uint32_t>(preview_.size());
+  size_ = preview_.size();
   valid_ = true;
 }
 
@@ -817,7 +817,7 @@ bool LoaderXmpJpeg::readDimensions() {
   return valid();
 }
 
-DataBuf decodeHex(const byte *src, long srcSize) {
+DataBuf decodeHex(const byte *src, size_t srcSize) {
   // create decoding table
   byte invalid = 16;
   std::array<byte, 256> decodeHexTable;
@@ -831,17 +831,17 @@ DataBuf decodeHex(const byte *src, long srcSize) {
 
   // calculate dest size
   long validSrcSize = 0;
-  for (long srcPos = 0; srcPos < srcSize; srcPos++) {
+  for (size_t srcPos = 0; srcPos < srcSize; srcPos++) {
     if (decodeHexTable[src[srcPos]] != invalid)
       validSrcSize++;
   }
-  const long destSize = validSrcSize / 2;
+  const size_t destSize = validSrcSize / 2;
 
   // allocate dest buffer
   DataBuf dest(destSize);
 
   // decode
-  for (long srcPos = 0, destPos = 0; destPos < destSize; destPos++) {
+  for (size_t srcPos = 0, destPos = 0; destPos < destSize; destPos++) {
     byte buffer = 0;
     for (int bufferPos = 1; bufferPos >= 0 && srcPos < srcSize; srcPos++) {
       byte srcValue = decodeHexTable[src[srcPos]];
@@ -880,7 +880,7 @@ DataBuf decodeBase64(const std::string &src) {
   // allocate dest buffer
   if (destSize > LONG_MAX)
     return {};  // avoid integer overflow
-  DataBuf dest(static_cast<long>(destSize));
+  DataBuf dest(destSize);
 
   // decode
   for (unsigned long srcPos = 0, destPos = 0; destPos < destSize;) {
@@ -901,7 +901,7 @@ DataBuf decodeBase64(const std::string &src) {
 
 DataBuf decodeAi7Thumbnail(const DataBuf &src) {
   const byte *colorTable = src.c_data();
-  const long colorTableSize = 256 * 3;
+  const size_t colorTableSize = 256 * 3;
   if (src.size() < colorTableSize) {
 #ifndef SUPPRESS_WARNINGS
     EXV_WARNING << "Invalid size of AI7 thumbnail: " << src.size() << "\n";
@@ -909,10 +909,10 @@ DataBuf decodeAi7Thumbnail(const DataBuf &src) {
     return {};
   }
   const byte *imageData = src.c_data(colorTableSize);
-  const long imageDataSize = static_cast<long>(src.size()) - colorTableSize;
+  const size_t imageDataSize = src.size() - colorTableSize;
   const bool rle = (imageDataSize >= 3 && imageData[0] == 'R' && imageData[1] == 'L' && imageData[2] == 'E');
   std::string dest;
-  for (long i = rle ? 3 : 0; i < imageDataSize;) {
+  for (size_t i = rle ? 3 : 0; i < imageDataSize;) {
     byte num = 1;
     byte value = imageData[i++];
     if (rle && value == 0xFD) {
@@ -1029,8 +1029,8 @@ PreviewPropertiesList PreviewManager::getPreviewProperties() const {
     auto loader = Loader::create(id, image_);
     if (loader && loader->readDimensions()) {
       PreviewProperties props = loader->getProperties();
-      DataBuf buf = loader->getData();                  // #16 getPreviewImage()
-      props.size_ = static_cast<uint32_t>(buf.size());  //     update the size
+      DataBuf buf = loader->getData();  // #16 getPreviewImage()
+      props.size_ = buf.size();         //     update the size
       list.push_back(props);
     }
   }
diff --git a/src/psdimage.cpp b/src/psdimage.cpp
index c3b6bebc..7f0c8155 100644
--- a/src/psdimage.cpp
+++ b/src/psdimage.cpp
@@ -217,7 +217,7 @@ void PsdImage::readResourceBlock(uint16_t resourceId, uint32_t resourceSize) {
       io_->read(rawIPTC.data(), rawIPTC.size());
       if (io_->error() || io_->eof())
         throw Error(ErrorCode::kerFailedToReadImageData);
-      if (IptcParser::decode(iptcData_, rawIPTC.c_data(), static_cast<uint32_t>(rawIPTC.size()))) {
+      if (IptcParser::decode(iptcData_, rawIPTC.c_data(), rawIPTC.size())) {
 #ifndef SUPPRESS_WARNINGS
         EXV_WARNING << "Failed to decode IPTC metadata.\n";
 #endif
@@ -484,8 +484,7 @@ void PsdImage::doWriteMetadata(BasicIo& outIo) {
       readTotal = 0;
       while (readTotal < pResourceSize) {
         /// \todo almost same code as in lines 403-410. Factor out & reuse!
-        size_t toRead = (pResourceSize - readTotal) < lbuf.size() ? static_cast<long>(pResourceSize - readTotal)
-                                                                  : static_cast<long>(lbuf.size());
+        size_t toRead = (pResourceSize - readTotal) < lbuf.size() ? pResourceSize - readTotal : lbuf.size();
         if (io_->read(lbuf.data(), toRead) != toRead) {
           throw Error(ErrorCode::kerNotAnImage, "Photoshop");
         }
diff --git a/src/tiffcomposite_int.cpp b/src/tiffcomposite_int.cpp
index 6f77f8f0..54a76e2c 100644
--- a/src/tiffcomposite_int.cpp
+++ b/src/tiffcomposite_int.cpp
@@ -217,7 +217,7 @@ void TiffEntryBase::setData(const std::shared_ptr<DataBuf>& buf) {
   size_ = buf->size();
 }
 
-void TiffEntryBase::setData(byte* pData, uint32_t size, const std::shared_ptr<DataBuf>& storage) {
+void TiffEntryBase::setData(byte* pData, size_t size, const std::shared_ptr<DataBuf>& storage) {
   pData_ = pData;
   size_ = size;
   storage_ = storage;
@@ -352,7 +352,7 @@ uint32_t TiffIfdMakernote::baseOffset() const {
   return pHeader_->baseOffset(mnOffset_);
 }
 
-bool TiffIfdMakernote::readHeader(const byte* pData, uint32_t size, ByteOrder byteOrder) {
+bool TiffIfdMakernote::readHeader(const byte* pData, size_t size, ByteOrder byteOrder) {
   if (!pHeader_)
     return true;
   return pHeader_->read(pData, size, byteOrder);
diff --git a/src/tiffcomposite_int.hpp b/src/tiffcomposite_int.hpp
index 7a8b1fed..ce412879 100644
--- a/src/tiffcomposite_int.hpp
+++ b/src/tiffcomposite_int.hpp
@@ -422,7 +422,7 @@ class TiffEntryBase : public TiffComponent {
                    you should pass std::shared_ptr<DataBuf>(), which is essentially
                    a nullptr.
    */
-  void setData(byte* pData, uint32_t size, const std::shared_ptr<DataBuf>& storage);
+  void setData(byte* pData, size_t size, const std::shared_ptr<DataBuf>& storage);
   /*!
     @brief Set the entry's data buffer. A shared_ptr is used to manage the DataBuf
            because TiffEntryBase has a clone method so it is possible (in theory) for
@@ -1113,7 +1113,7 @@ class TiffIfdMakernote : public TiffComponent {
 
     The default implementation simply returns true.
    */
-  bool readHeader(const byte* pData, uint32_t size, ByteOrder byteOrder);
+  bool readHeader(const byte* pData, size_t size, ByteOrder byteOrder);
   /*!
     @brief Set the byte order for the makernote.
    */
diff --git a/src/tiffimage.cpp b/src/tiffimage.cpp
index af047cac..3d80c6d5 100644
--- a/src/tiffimage.cpp
+++ b/src/tiffimage.cpp
@@ -220,8 +220,7 @@ ByteOrder TiffParser::decode(ExifData& exifData, IptcData& iptcData, XmpData& xm
     }
   }
 
-  return TiffParserWorker::decode(exifData, iptcData, xmpData, pData, static_cast<uint32_t>(size), root,
-                                  TiffMapping::findDecoder);
+  return TiffParserWorker::decode(exifData, iptcData, xmpData, pData, size, root, TiffMapping::findDecoder);
 }  // TiffParser::decode
 
 WriteMethod TiffParser::encode(BasicIo& io, const byte* pData, size_t size, ByteOrder byteOrder,
diff --git a/src/tiffvisitor_int.cpp b/src/tiffvisitor_int.cpp
index 38e1fe09..4b097db7 100644
--- a/src/tiffvisitor_int.cpp
+++ b/src/tiffvisitor_int.cpp
@@ -310,7 +310,7 @@ void TiffDecoder::decodeIptc(const TiffEntryBase* object) {
   size_t size = 0;
   getObjData(pData, size, 0x83bb, ifd0Id, object);
   if (pData) {
-    if (0 == IptcParser::decode(iptcData_, pData, static_cast<uint32_t>(size))) {
+    if (0 == IptcParser::decode(iptcData_, pData, size)) {
       return;
     }
 #ifndef SUPPRESS_WARNINGS
@@ -516,7 +516,7 @@ void TiffEncoder::encodeIptc() {
     } else {
       buf = std::move(rawIptc);  // Note: This resets rawIptc
     }
-    value->read(buf.data(), static_cast<long>(buf.size()), byteOrder_);
+    value->read(buf.data(), buf.size(), byteOrder_);
     Exifdatum iptcDatum(iptcNaaKey, value.get());
     exifData_.add(iptcDatum);
     pos = exifData_.findKey(irbKey);  // needed after add()
@@ -530,7 +530,7 @@ void TiffEncoder::encodeIptc() {
     exifData_.erase(pos);
     if (!irbBuf.empty()) {
       auto value = Value::create(unsignedByte);
-      value->read(irbBuf.data(), static_cast<long>(irbBuf.size()), invalidByteOrder);
+      value->read(irbBuf.data(), irbBuf.size(), invalidByteOrder);
       Exifdatum iptcDatum(irbKey, value.get());
       exifData_.add(iptcDatum);
     }
@@ -559,7 +559,7 @@ void TiffEncoder::encodeXmp() {
   if (!xmpPacket.empty()) {
     // Set the XMP Exif tag to the new value
     auto value = Value::create(unsignedByte);
-    value->read(reinterpret_cast<const byte*>(&xmpPacket[0]), static_cast<long>(xmpPacket.size()), invalidByteOrder);
+    value->read(reinterpret_cast<const byte*>(&xmpPacket[0]), xmpPacket.size(), invalidByteOrder);
     Exifdatum xmpDatum(xmpKey, value.get());
     exifData_.add(xmpDatum);
   }
@@ -697,7 +697,7 @@ void TiffEncoder::visitBinaryArrayEnd(TiffBinaryArray* object) {
     DataBuf buf = cryptFct(object->tag(), pData, size, pRoot_);
     if (!buf.empty()) {
       pData = buf.c_data();
-      size = static_cast<int32_t>(buf.size());
+      size = buf.size();
     }
     if (!object->updOrigDataBuf(pData, size)) {
       setDirty();
@@ -837,7 +837,7 @@ void TiffEncoder::encodeImageEntry(TiffImageEntry* object, const Exifdatum* datu
       uint32_t sizeTotal = 0;
       object->strips_.clear();
       for (size_t i = 0; i < pos->count(); ++i) {
-        uint32_t len = pos->toUint32(static_cast<long>(i));
+        uint32_t len = pos->toUint32(i);
         object->strips_.emplace_back(zero, len);
         sizeTotal += len;
       }
@@ -1225,12 +1225,12 @@ void TiffReader::visitMnEntry(TiffMnEntry* object) {
 void TiffReader::visitIfdMakernote(TiffIfdMakernote* object) {
   object->setImageByteOrder(byteOrder());  // set the byte order for the image
 
-  if (!object->readHeader(object->start(), static_cast<uint32_t>(pLast_ - object->start()), byteOrder())) {
+  if (!object->readHeader(object->start(), pLast_ - object->start(), byteOrder())) {
 #ifndef SUPPRESS_WARNINGS
     EXV_ERROR << "Failed to read " << groupName(object->ifd_.group()) << " IFD Makernote header.\n";
 #ifdef EXIV2_DEBUG_MESSAGES
-    if (static_cast<uint32_t>(pLast_ - object->start()) >= 16) {
-      hexdump(std::cerr, object->start(), 16);
+    if (pLast_ - object->start() >= 16u) {
+      hexdump(std::cerr, object->start(), 16u);
     }
 #endif  // EXIV2_DEBUG_MESSAGES
 #endif  // SUPPRESS_WARNINGS
@@ -1291,10 +1291,10 @@ void TiffReader::readTiffEntry(TiffEntryBase* object) {
   if (count > std::numeric_limits<uint32_t>::max() / typeSize) {
     throw Error(ErrorCode::kerArithmeticOverflow);
   }
-  auto size = static_cast<uint32_t>(typeSize * count);
+  size_t size = typeSize * count;
   uint32_t offset = getLong(p, byteOrder());
   byte* pData = p;
-  if (size > 4 && (baseOffset() + offset >= size_ || static_cast<int32_t>(baseOffset()) + offset <= 0)) {
+  if (size > 4 && (baseOffset() + offset >= size_ || baseOffset() + offset <= 0)) {
     // #1143
     if (object->tag() == 0x2001 && std::string(groupName(object->group())) == "Sony1") {
       // This tag is Exif.Sony1.PreviewImage, which refers to a preview image which is
@@ -1335,7 +1335,7 @@ void TiffReader::readTiffEntry(TiffEntryBase* object) {
     pData = const_cast<byte*>(pData_) + baseOffset() + offset;
 
     // check for size being invalid
-    if (size > static_cast<uint32_t>(pLast_ - pData)) {
+    if (size > static_cast<size_t>(pLast_ - pData)) {
 #ifndef SUPPRESS_WARNINGS
       EXV_ERROR << "Upper boundary of data for "
                 << "directory " << groupName(object->group()) << ", entry 0x" << std::setw(4) << std::setfill('0')
diff --git a/src/value.cpp b/src/value.cpp
index 5184c042..7a722ed0 100644
--- a/src/value.cpp
+++ b/src/value.cpp
@@ -155,8 +155,8 @@ DataValue* DataValue::clone_() const {
 }
 
 std::ostream& DataValue::write(std::ostream& os) const {
-  std::vector<byte>::size_type end = value_.size();
-  for (std::vector<byte>::size_type i = 0; i != end; ++i) {
+  size_t end = value_.size();
+  for (size_t i = 0; i != end; ++i) {
     os << static_cast<int>(value_.at(i));
     if (i < end - 1)
       os << " ";
diff --git a/src/webpimage.cpp b/src/webpimage.cpp
index 020e6975..0c4cb505 100644
--- a/src/webpimage.cpp
+++ b/src/webpimage.cpp
@@ -184,10 +184,8 @@ void WebPImage::doWriteMetadata(BasicIo& outIo) {
     const uint32_t size_u32 = Exiv2::getULong(size_buff, littleEndian);
 
     // Check that `size_u32` is safe to cast to `long`.
-    enforce(size_u32 <= static_cast<size_t>(std::numeric_limits<unsigned int>::max()),
-            Exiv2::ErrorCode::kerCorruptedMetadata);
-    const auto size = static_cast<long>(size_u32);
-    DataBuf payload(size);
+    enforce(size_u32 <= std::numeric_limits<uint32_t>::max(), Exiv2::ErrorCode::kerCorruptedMetadata);
+    DataBuf payload(size_u32);
     io_->readOrThrow(payload.data(), payload.size(), Exiv2::ErrorCode::kerCorruptedMetadata);
     if (payload.size() % 2) {
       byte c = 0;
@@ -200,7 +198,7 @@ void WebPImage::doWriteMetadata(BasicIo& outIo) {
       has_vp8x = true;
     }
     if (equalsWebPTag(chunkId, WEBP_CHUNK_HEADER_VP8X) && !has_size) {
-      enforce(size >= 10, Exiv2::ErrorCode::kerCorruptedMetadata);
+      enforce(size_u32 >= 10, Exiv2::ErrorCode::kerCorruptedMetadata);
       has_size = true;
       byte size_buf[WEBP_TAG_SIZE];
 
@@ -229,7 +227,7 @@ void WebPImage::doWriteMetadata(BasicIo& outIo) {
     }
 #endif
     if (equalsWebPTag(chunkId, WEBP_CHUNK_HEADER_VP8) && !has_size) {
-      enforce(size >= 10, Exiv2::ErrorCode::kerCorruptedMetadata);
+      enforce(size_u32 >= 10, Exiv2::ErrorCode::kerCorruptedMetadata);
       has_size = true;
       byte size_buf[2];
 
@@ -247,13 +245,13 @@ void WebPImage::doWriteMetadata(BasicIo& outIo) {
 
     /* Chunk with lossless image data. */
     if (equalsWebPTag(chunkId, WEBP_CHUNK_HEADER_VP8L) && !has_alpha) {
-      enforce(size >= 5, Exiv2::ErrorCode::kerCorruptedMetadata);
+      enforce(size_u32 >= 5, Exiv2::ErrorCode::kerCorruptedMetadata);
       if ((payload.read_uint8(4) & WEBP_VP8X_ALPHA_BIT) == WEBP_VP8X_ALPHA_BIT) {
         has_alpha = true;
       }
     }
     if (equalsWebPTag(chunkId, WEBP_CHUNK_HEADER_VP8L) && !has_size) {
-      enforce(size >= 5, Exiv2::ErrorCode::kerCorruptedMetadata);
+      enforce(size_u32 >= 5, Exiv2::ErrorCode::kerCorruptedMetadata);
       has_size = true;
       byte size_buf_w[2];
       byte size_buf_h[3];
@@ -277,13 +275,13 @@ void WebPImage::doWriteMetadata(BasicIo& outIo) {
 
     /* Chunk with animation frame. */
     if (equalsWebPTag(chunkId, WEBP_CHUNK_HEADER_ANMF) && !has_alpha) {
-      enforce(size >= 6, Exiv2::ErrorCode::kerCorruptedMetadata);
+      enforce(size_u32 >= 6, Exiv2::ErrorCode::kerCorruptedMetadata);
       if ((payload.read_uint8(5) & 0x2) == 0x2) {
         has_alpha = true;
       }
     }
     if (equalsWebPTag(chunkId, WEBP_CHUNK_HEADER_ANMF) && !has_size) {
-      enforce(size >= 12, Exiv2::ErrorCode::kerCorruptedMetadata);
+      enforce(size_u32 >= 12, Exiv2::ErrorCode::kerCorruptedMetadata);
       has_size = true;
       byte size_buf[WEBP_TAG_SIZE];
 
@@ -317,17 +315,15 @@ void WebPImage::doWriteMetadata(BasicIo& outIo) {
     const uint32_t size_u32 = Exiv2::getULong(size_buff, littleEndian);
 
     // Check that `size_u32` is safe to cast to `long`.
-    enforce(size_u32 <= static_cast<size_t>(std::numeric_limits<unsigned int>::max()),
-            Exiv2::ErrorCode::kerCorruptedMetadata);
-    const auto size = static_cast<long>(size_u32);
+    enforce(size_u32 <= std::numeric_limits<uint32_t>::max(), Exiv2::ErrorCode::kerCorruptedMetadata);
 
-    DataBuf payload(size);
-    io_->readOrThrow(payload.data(), size, Exiv2::ErrorCode::kerCorruptedMetadata);
+    DataBuf payload(size_u32);
+    io_->readOrThrow(payload.data(), size_u32, Exiv2::ErrorCode::kerCorruptedMetadata);
     if (io_->tell() % 2)
       io_->seek(+1, BasicIo::cur);  // skip pad
 
     if (equalsWebPTag(chunkId, WEBP_CHUNK_HEADER_VP8X)) {
-      enforce(size >= 1, Exiv2::ErrorCode::kerCorruptedMetadata);
+      enforce(size_u32 >= 1, Exiv2::ErrorCode::kerCorruptedMetadata);
       if (has_icc) {
         const uint8_t x = payload.read_uint8(0);
         payload.write_uint8(0, x | WEBP_VP8X_ICC_BIT);
@@ -643,26 +639,22 @@ void WebPImage::decodeChunks(long filesize) {
       bool s_header = false;
       bool le_header = false;
       bool be_header = false;
-      long pos = getHeaderOffset(payload.c_data(), static_cast<long>(payload.size()),
-                                 reinterpret_cast<byte*>(&exifLongHeader), 4);
+      long pos = getHeaderOffset(payload.c_data(), payload.size(), reinterpret_cast<byte*>(&exifLongHeader), 4);
 
       if (pos == -1) {
-        pos = getHeaderOffset(payload.c_data(), static_cast<long>(payload.size()),
-                              reinterpret_cast<byte*>(&exifLongHeader), 6);
+        pos = getHeaderOffset(payload.c_data(), payload.size(), reinterpret_cast<byte*>(&exifLongHeader), 6);
         if (pos != -1) {
           s_header = true;
         }
       }
       if (pos == -1) {
-        pos = getHeaderOffset(payload.c_data(), static_cast<long>(payload.size()),
-                              reinterpret_cast<byte*>(&exifTiffLEHeader), 3);
+        pos = getHeaderOffset(payload.c_data(), payload.size(), reinterpret_cast<byte*>(&exifTiffLEHeader), 3);
         if (pos != -1) {
           le_header = true;
         }
       }
       if (pos == -1) {
-        pos = getHeaderOffset(payload.c_data(), static_cast<long>(payload.size()),
-                              reinterpret_cast<byte*>(&exifTiffBEHeader), 4);
+        pos = getHeaderOffset(payload.c_data(), payload.size(), reinterpret_cast<byte*>(&exifTiffBEHeader), 4);
         if (pos != -1) {
           be_header = true;
         }
@@ -835,14 +827,14 @@ void WebPImage::inject_VP8X(BasicIo& iIo, bool has_xmp, bool has_exif, bool has_
   }
 }
 
-long WebPImage::getHeaderOffset(const byte* data, long data_size, const byte* header, long header_size) {
+long WebPImage::getHeaderOffset(const byte* data, size_t data_size, const byte* header, size_t header_size) {
   if (data_size < header_size) {
     return -1;
   }
   long pos = -1;
-  for (long i = 0; i < data_size - header_size; i++) {
+  for (size_t i = 0; i < data_size - header_size; i++) {
     if (memcmp(header, &data[i], header_size) == 0) {
-      pos = i;
+      pos = static_cast<long>(i);
       break;
     }
   }
diff --git a/unitTests/test_bmpimage.cpp b/unitTests/test_bmpimage.cpp
index 88511f98..31307dfe 100644
--- a/unitTests/test_bmpimage.cpp
+++ b/unitTests/test_bmpimage.cpp
@@ -85,7 +85,7 @@ TEST(BmpImage, readMetadataReadsImageDimensionsWhenDataIsAvailable) {
       0x20, 0x03, 0x00, 0x00,  // The bitmap height in pixels (unsigned 16 bit)                     off:22, size:4
   };
 
-  auto memIo = std::make_unique<MemIo>(header.data(), static_cast<long>(header.size()));
+  auto memIo = std::make_unique<MemIo>(header.data(), header.size());
   BmpImage bmp(std::move(memIo));
   ASSERT_NO_THROW(bmp.readMetadata());
   ASSERT_EQ(1280, bmp.pixelWidth());
@@ -104,7 +104,7 @@ TEST(BmpImage, readMetadataThrowsWhenImageIsNotBMP) {
       0x20, 0x03, 0x00, 0x00,  // The bitmap height in pixels (unsigned 16 bit)                     off:22, size:4
   };
 
-  auto memIo = std::make_unique<MemIo>(header.data(), static_cast<long>(header.size()));
+  auto memIo = std::make_unique<MemIo>(header.data(), header.size());
   BmpImage bmp(std::move(memIo));
   try {
     bmp.readMetadata();
@@ -117,7 +117,7 @@ TEST(BmpImage, readMetadataThrowsWhenImageIsNotBMP) {
 
 TEST(BmpImage, readMetadataThrowsWhenThereIsNotEnoughInfoToRead) {
   const std::array<unsigned char, 1> header{'B'};
-  auto memIo = std::make_unique<MemIo>(header.data(), static_cast<long>(header.size()));
+  auto memIo = std::make_unique<MemIo>(header.data(), header.size());
   BmpImage bmp(std::move(memIo));
   try {
     bmp.readMetadata();
@@ -147,7 +147,7 @@ TEST(newBmpInstance, createsValidInstace) {
       0x00, 0x00,              // Reserved
       0x00, 0x00, 0x00, 0x00   // Offset of the byte where the bitmap image data can be found
   };
-  auto memIo = std::make_unique<MemIo>(bitmapHeader.data(), static_cast<long>(bitmapHeader.size()));
+  auto memIo = std::make_unique<MemIo>(bitmapHeader.data(), bitmapHeader.size());
   auto img = newBmpInstance(std::move(memIo), false);
   ASSERT_TRUE(img->good());
 }
@@ -166,7 +166,7 @@ TEST(isBmpType, withValidSignatureReturnsTrue) {
       0x00, 0x00,              // Reserved
       0x00, 0x00, 0x00, 0x00   // Offset of the byte where the bitmap image data can be found
   };
-  MemIo memIo(bitmapHeader.data(), static_cast<long>(bitmapHeader.size()));
+  MemIo memIo(bitmapHeader.data(), bitmapHeader.size());
   ASSERT_TRUE(isBmpType(memIo, false));
 }
 
@@ -178,6 +178,6 @@ TEST(isBmpType, withInvalidSignatureReturnsFalse) {
       0x00, 0x00,              // Reserved
       0x00, 0x00, 0x00, 0x00   // Offset of the byte where the bitmap image data can be found
   };
-  MemIo memIo(bitmapHeader.data(), static_cast<long>(bitmapHeader.size()));
+  MemIo memIo(bitmapHeader.data(), bitmapHeader.size());
   ASSERT_FALSE(isBmpType(memIo, false));
 }
diff --git a/unitTests/test_pngimage.cpp b/unitTests/test_pngimage.cpp
index 9dd0b04c..abeb464d 100644
--- a/unitTests/test_pngimage.cpp
+++ b/unitTests/test_pngimage.cpp
@@ -18,7 +18,7 @@ TEST(PngChunk, keyTxtChunkExtractsKeywordCorrectlyInPresenceOfNullChar) {
                                           0x20, 0x70, 0x72, 0x6f, 0x66, 0x69, 0x6c, 0x65, 0x20, 0x74, 0x79,
                                           0x70, 0x65, 0x20, 0x65, 0x78, 0x69, 0x66, 0x00, 0x00, 0x78};
 
-  DataBuf chunkBuf(data.data(), static_cast<long>(data.size()));
+  DataBuf chunkBuf(data.data(), data.size());
   DataBuf key = Internal::PngChunk::keyTXTChunk(chunkBuf, true);
   ASSERT_EQ(21, key.size());
 
@@ -31,13 +31,13 @@ TEST(PngChunk, keyTxtChunkThrowsExceptionWhenThereIsNoNullChar) {
                                           0x77, 0x20, 0x70, 0x72, 0x6f, 0x66, 0x69, 0x6c, 0x65, 0x20,
                                           0x74, 0x79, 0x70, 0x65, 0x20, 0x65, 0x78, 0x69, 0x66, 0x78};
 
-  DataBuf chunkBuf(data.data(), static_cast<long>(data.size()));
+  DataBuf chunkBuf(data.data(), data.size());
   ASSERT_THROW(Internal::PngChunk::keyTXTChunk(chunkBuf, true), Exiv2::Error);
 }
 
 TEST(PngChunk, keyTxtChunkThrowsIfSizeIsNotEnough) {
   const std::array<std::uint8_t, 4> data{0x00, 0x00, 0x22, 0x41};
-  DataBuf chunkBuf(data.data(), static_cast<long>(data.size()));
+  DataBuf chunkBuf(data.data(), data.size());
   ASSERT_THROW(Internal::PngChunk::keyTXTChunk(chunkBuf, true), Exiv2::Error);
 
   DataBuf emptyChunk(data.data(), 0);