diff --git a/app/app_utils.cpp b/app/app_utils.cpp
index d36694b2d1..e2fedf9996 100644
--- a/app/app_utils.cpp
+++ b/app/app_utils.cpp
@@ -2,6 +2,7 @@
 
 #include "app_utils.hpp"
 #include <climits>
+#include <cstdint>
 #include <cstdlib>
 #include <limits>
 
diff --git a/app/exiv2app.hpp b/app/exiv2app.hpp
index 8e7dcdd033..6fbfb38abe 100644
--- a/app/exiv2app.hpp
+++ b/app/exiv2app.hpp
@@ -13,7 +13,6 @@
 #include <exiv2/exiv2.hpp>
 
 #include "getopt.hpp"
-#include "types.hpp"
 
 // + standard includes
 #include <iostream>
diff --git a/src/basicio.cpp b/src/basicio.cpp
index e44c0372b8..7b092c6a74 100644
--- a/src/basicio.cpp
+++ b/src/basicio.cpp
@@ -931,13 +931,13 @@ std::string XPathIo::writeDataToFile(const std::string& orgPath) {
 #endif
     std::ofstream fs(path, std::ios::out | std::ios::binary | std::ios::trunc);
     // read stdin and write to the temp file.
-    char readBuf[100 * 1024];
+    auto readBuf = std::make_unique<char[]>(100 * 1024);
     std::streamsize readBufSize = 0;
     do {
-      std::cin.read(readBuf, sizeof(readBuf));
+      std::cin.read(readBuf.get(), 100 * 1024);
       readBufSize = std::cin.gcount();
       if (readBufSize > 0) {
-        fs.write(readBuf, readBufSize);
+        fs.write(readBuf.get(), readBufSize);
       }
     } while (readBufSize);
     fs.close();
diff --git a/src/convert.cpp b/src/convert.cpp
index 1cc31b2beb..0cd22f4f64 100644
--- a/src/convert.cpp
+++ b/src/convert.cpp
@@ -751,7 +751,7 @@ void Converter::cnvExifVersion(const char* from, const char* to) {
   std::string value;
   value.reserve(count);
   for (size_t i = 0; i < count; ++i) {
-    value.push_back(pos->toInt64(i));
+    value.push_back(pos->toUint32(i));
   }
   (*xmpData_)[to] = value;
   if (erase_)
diff --git a/src/crwimage_int.cpp b/src/crwimage_int.cpp
index d6f2acfaad..8657f74414 100644
--- a/src/crwimage_int.cpp
+++ b/src/crwimage_int.cpp
@@ -135,6 +135,8 @@ const CiffComponent::UniquePtr& CiffDirectory::doAdd(UniquePtr component) {
   return components_.emplace_back(std::move(component));
 }  // CiffDirectory::doAdd
 
+const byte CiffHeader::signature_[] = {'H', 'E', 'A', 'P', 'C', 'C', 'D', 'R'};
+
 void CiffHeader::read(const byte* pData, size_t size) {
   if (size < 14)
     throw Error(ErrorCode::kerNotACrwImage);
@@ -281,7 +283,7 @@ void CiffHeader::write(Blob& blob) const {
   ul2Data(buf, offset_, byteOrder_);
   append(blob, buf, 4);
   o += 4;
-  append(blob, reinterpret_cast<const byte*>(signature_), 8);
+  append(blob, signature_, 8);
   o += 8;
   // Pad as needed
   if (!pPadding_.empty()) {
diff --git a/src/crwimage_int.hpp b/src/crwimage_int.hpp
index c086bc7f17..f51fd585e9 100644
--- a/src/crwimage_int.hpp
+++ b/src/crwimage_int.hpp
@@ -413,7 +413,7 @@ class CiffHeader {
   //@}
 
   //! Return a pointer to the Canon CRW signature.
-  static const char* signature() {
+  static auto signature() {
     return signature_;
   }
 
@@ -451,7 +451,7 @@ class CiffHeader {
 
  private:
   // DATA
-  static constexpr auto signature_ = "HEAPCCDR";  //!< Canon CRW signature
+  static const byte signature_[];  //!< Canon CRW signature
 
   std::unique_ptr<CiffDirectory> pRootDir_;  //!< Pointer to the root directory
   ByteOrder byteOrder_ = littleEndian;       //!< Applicable byte order
diff --git a/src/error.cpp b/src/error.cpp
index 5235b12b06..d4b2008722 100644
--- a/src/error.cpp
+++ b/src/error.cpp
@@ -7,6 +7,8 @@
 // + standard includes
 #include <array>
 #include <iostream>
+#include <string>
+#include <utility>
 
 namespace {
 //! Complete list of Exiv2 exception error messages
diff --git a/src/pgfimage.cpp b/src/pgfimage.cpp
index 394cf1d9e0..187d8e15fc 100644
--- a/src/pgfimage.cpp
+++ b/src/pgfimage.cpp
@@ -9,10 +9,13 @@
 #include "error.hpp"
 #include "futils.hpp"
 #include "image.hpp"
+#include "types.hpp"
 
 #include <array>
+#include <cstdint>
 #include <cstring>
 #include <limits>
+#include <utility>
 
 #ifdef EXIV2_DEBUG_MESSAGES
 #include <iostream>
diff --git a/src/quicktimevideo.cpp b/src/quicktimevideo.cpp
index 583f595937..88ac1e92bf 100644
--- a/src/quicktimevideo.cpp
+++ b/src/quicktimevideo.cpp
@@ -1430,9 +1430,7 @@ void QuickTimeVideo::mediaHeaderDecoder(size_t size) {
           xmpData_["Xmp.video.MediaTimeScale"] = buf.read_uint32(0, bigEndian);
         else if (currentStream_ == Audio)
           xmpData_["Xmp.audio.MediaTimeScale"] = buf.read_uint32(0, bigEndian);
-        time_scale = buf.read_uint32(0, bigEndian);
-        if (time_scale <= 0)
-          time_scale = 1;
+        time_scale = std::max(1U, buf.read_uint32(0, bigEndian));
         break;
       case MediaDuration:
         if (currentStream_ == Video)
@@ -1551,9 +1549,7 @@ void QuickTimeVideo::movieHeaderDecoder(size_t size) {
         break;
       case TimeScale:
         xmpData_["Xmp.video.TimeScale"] = buf.read_uint32(0, bigEndian);
-        timeScale_ = buf.read_uint32(0, bigEndian);
-        if (timeScale_ <= 0)
-          timeScale_ = 1;
+        timeScale_ = std::max(1U, buf.read_uint32(0, bigEndian));
         break;
       case Duration:
         if (timeScale_ != 0) {  // To prevent division by zero
diff --git a/src/sonymn_int.hpp b/src/sonymn_int.hpp
index faa347845b..10aaecde06 100644
--- a/src/sonymn_int.hpp
+++ b/src/sonymn_int.hpp
@@ -12,6 +12,7 @@
 namespace Exiv2 {
 class ExifData;
 class Value;
+struct DataBuf;
 struct TagInfo;
 namespace Internal {
 // *****************************************************************************
@@ -144,8 +145,8 @@ class SonyMakerNote {
 
 };  // class SonyMakerNote
 
-DataBuf sonyTagDecipher(uint16_t, const byte*, size_t, TiffComponent*);
-DataBuf sonyTagEncipher(uint16_t, const byte*, size_t, TiffComponent*);
+DataBuf sonyTagDecipher(uint16_t, const unsigned char*, size_t, TiffComponent*);
+DataBuf sonyTagEncipher(uint16_t, const unsigned char*, size_t, TiffComponent*);
 
 }  // namespace Internal
 }  // namespace Exiv2
diff --git a/src/tags.cpp b/src/tags.cpp
index 885a799793..4149cad8a6 100644
--- a/src/tags.cpp
+++ b/src/tags.cpp
@@ -74,18 +74,16 @@ bool GroupInfo::operator==(const GroupName& groupName) const {
 }
 
 const char* ExifTags::sectionName(const ExifKey& key) {
-  const TagInfo* ti = tagInfo(key.tag(), key.ifdId());
-  if (!ti)
-    return sectionInfo[static_cast<int>(unknownTag.sectionId_)].name_;
-  return sectionInfo[static_cast<int>(ti->sectionId_)].name_;
+  if (auto ti = tagInfo(key.tag(), key.ifdId()))
+    return sectionInfo[static_cast<int>(ti->sectionId_)].name_;
+  return sectionInfo[static_cast<int>(unknownTag.sectionId_)].name_;
 }
 
 /// \todo not used internally. At least we should test it
 uint16_t ExifTags::defaultCount(const ExifKey& key) {
-  const TagInfo* ti = tagInfo(key.tag(), key.ifdId());
-  if (!ti)
-    return unknownTag.count_;
-  return ti->count_;
+  if (auto ti = tagInfo(key.tag(), key.ifdId()))
+    return ti->count_;
+  return unknownTag.count_;
 }
 
 const char* ExifTags::ifdName(const std::string& groupName) {
@@ -236,12 +234,12 @@ ExifKey::ExifKey(uint16_t tag, const std::string& groupName) : p_(std::make_uniq
   if (!Internal::isExifIfd(ifdId) && !Internal::isMakerIfd(ifdId)) {
     throw Error(ErrorCode::kerInvalidIfdId, ifdId);
   }
-  const TagInfo* ti = tagInfo(tag, ifdId);
-  if (!ti) {
-    throw Error(ErrorCode::kerInvalidIfdId, ifdId);
+  if (auto ti = tagInfo(tag, ifdId)) {
+    p_->groupName_ = groupName;
+    p_->makeKey(tag, ifdId, ti);
+    return;
   }
-  p_->groupName_ = groupName;
-  p_->makeKey(tag, ifdId, ti);
+  throw Error(ErrorCode::kerInvalidIfdId, ifdId);
 }
 
 ExifKey::ExifKey(const TagInfo& ti) : p_(std::make_unique<Impl>()) {
diff --git a/src/tags_int.cpp b/src/tags_int.cpp
index 10c1dcf95d..cae603e521 100644
--- a/src/tags_int.cpp
+++ b/src/tags_int.cpp
@@ -2474,8 +2474,9 @@ const TagInfo* mnTagList() {
 }
 
 bool isMakerIfd(IfdId ifdId) {
-  auto ii = Exiv2::find(groupInfo, ifdId);
-  return ii && strcmp(ii->ifdName_, "Makernote") == 0;
+  if (auto ii = Exiv2::find(groupInfo, ifdId))
+    return std::string_view("Makernote") == ii->ifdName_;
+  return false;
 }
 
 bool isExifIfd(IfdId ifdId) {
@@ -2620,7 +2621,7 @@ URational exposureTime(float shutterSpeedValue) {
 }
 
 uint16_t tagNumber(const std::string& tagName, IfdId ifdId) {
-  const TagInfo* ti = tagInfo(tagName, ifdId);
+  auto ti = tagInfo(tagName, ifdId);
   if (ti && ti->tag_ != 0xffff)
     return ti->tag_;
   if (!isHex(tagName, 4, "0x"))
diff --git a/src/tags_int.hpp b/src/tags_int.hpp
index e20c1b6983..6fa35360da 100644
--- a/src/tags_int.hpp
+++ b/src/tags_int.hpp
@@ -5,7 +5,6 @@
 
 // *****************************************************************************
 // included header files
-#include "types.hpp"
 #include "value.hpp"
 
 #include "i18n.h"
diff --git a/src/tiffcomposite_int.cpp b/src/tiffcomposite_int.cpp
index ae0d2c1b22..24436c020b 100644
--- a/src/tiffcomposite_int.cpp
+++ b/src/tiffcomposite_int.cpp
@@ -17,10 +17,17 @@
 #include "value.hpp"
 
 #include <algorithm>
+#include <cmath>
+#include <cstdint>
+#include <cstring>
 #include <functional>
+#include <iomanip>
 #include <iostream>
+#include <limits>
 #include <memory>
 #include <numeric>
+#include <string>
+#include <utility>
 
 // *****************************************************************************
 namespace {
@@ -1431,14 +1438,10 @@ static const TagInfo* findTagInfo(uint16_t tag, IfdId group) {
       return Internal::gpsTagList();
     return group == IfdId::exifId ? Internal::exifTagList() : nullptr;
   }();
-  if (!tags)
-    return nullptr;
-
-  for (size_t idx = 0; tags[idx].tag_ != 0xffff; ++idx) {
-    if (tags[idx].tag_ == tag) {
-      return tags + idx;
-    }
-  }
+  if (tags)
+    for (size_t idx = 0; tags[idx].tag_ != 0xffff; ++idx)
+      if (tags[idx].tag_ == tag)
+        return tags + idx;
   return nullptr;
 }
 
diff --git a/src/tiffcomposite_int.hpp b/src/tiffcomposite_int.hpp
index 7bbd3d3aff..87e0e9db81 100644
--- a/src/tiffcomposite_int.hpp
+++ b/src/tiffcomposite_int.hpp
@@ -6,6 +6,7 @@
 // *****************************************************************************
 // included header files
 #include "tifffwd_int.hpp"
+#include "types.hpp"
 
 #include <memory>
 
diff --git a/src/tifffwd_int.hpp b/src/tifffwd_int.hpp
index a8083c8fe3..e14e1797a6 100644
--- a/src/tifffwd_int.hpp
+++ b/src/tifffwd_int.hpp
@@ -5,7 +5,6 @@
 
 // *****************************************************************************
 // included header files
-#include "types.hpp"
 
 // + standard includes
 #include <memory>
diff --git a/src/tiffimage_int.hpp b/src/tiffimage_int.hpp
index 9880bc6f1c..1de0475aca 100644
--- a/src/tiffimage_int.hpp
+++ b/src/tiffimage_int.hpp
@@ -6,6 +6,7 @@
 // *****************************************************************************
 // included header files
 #include "tifffwd_int.hpp"
+#include "types.hpp"
 
 #include <map>
 #include <unordered_map>
@@ -17,6 +18,7 @@ class BasicIo;
 class ExifData;
 class IptcData;
 class XmpData;
+struct DataBuf;
 
 namespace Internal {
 /*!
diff --git a/src/tiffvisitor_int.cpp b/src/tiffvisitor_int.cpp
index 7c59309633..05e880b5a0 100644
--- a/src/tiffvisitor_int.cpp
+++ b/src/tiffvisitor_int.cpp
@@ -355,7 +355,7 @@ void TiffDecoder::decodeCanonAFInfo(const TiffEntryBase* object) {
   std::vector<uint16_t> uint;
   for (size_t i = 0; i < object->pValue()->count(); i++) {
     ints.push_back(object->pValue()->toInt64(i));
-    uint.push_back(object->pValue()->toInt64(i));
+    uint.push_back(object->pValue()->toUint32(i));
   }
   // Check this is AFInfo2 (ints[0] = bytes in object)
   if (ints.front() != static_cast<int16_t>(object->pValue()->count()) * 2)
@@ -393,7 +393,7 @@ void TiffDecoder::decodeCanonAFInfo(const TiffEntryBase* object) {
   }
 
   for (const auto& [tag, size, bSigned] : records) {
-    const TagInfo* pTags = ExifTags::tagList("Canon");
+    auto pTags = ExifTags::tagList("Canon");
     if (auto pTag = findTag(pTags, tag)) {
       auto v = Exiv2::Value::create(bSigned ? Exiv2::signedShort : Exiv2::unsignedShort);
       std::string s;
diff --git a/src/types.cpp b/src/types.cpp
index cb110c26bb..8f2c5c5d9b 100644
--- a/src/types.cpp
+++ b/src/types.cpp
@@ -211,8 +211,7 @@ std::ostream& operator<<(std::ostream& os, const Rational& r) {
   return os << r.first << "/" << r.second;
 }
 
-template <typename T>
-static std::istream& fromStreamToRational(std::istream& is, T& r) {
+static std::istream& fromStreamToRational(std::istream& is, auto& r) {
   // http://dev.exiv2.org/boards/3/topics/1912?r=1915
   if (std::tolower(is.peek()) == 'f') {
     char F = 0;
diff --git a/src/utils.hpp b/src/utils.hpp
index 02a41ac709..a3297b4b11 100644
--- a/src/utils.hpp
+++ b/src/utils.hpp
@@ -6,8 +6,7 @@
 
 namespace Exiv2::Internal {
 
-template <typename T>
-constexpr bool contains(std::string_view s, T c) {
+constexpr bool contains(std::string_view s, auto c) {
 #ifdef __cpp_lib_string_contains
   return s.contains(c);
 #else
diff --git a/src/webpimage.cpp b/src/webpimage.cpp
index cd89c1b30f..3771101219 100644
--- a/src/webpimage.cpp
+++ b/src/webpimage.cpp
@@ -21,8 +21,9 @@
 #include <cstring>
 #include <iostream>
 
+#ifdef EXIV2_DEBUG_MESSAGES
 namespace {
-[[maybe_unused]] std::string binaryToHex(const uint8_t* data, size_t size) {
+std::string binaryToHex(const uint8_t* data, size_t size) {
   std::stringstream hexOutput;
 
   auto tl = size / 16 * 16;
@@ -67,6 +68,7 @@ namespace {
   return hexOutput.str();
 }
 }  // namespace
+#endif
 
 // *****************************************************************************
 // class member definitions
diff --git a/src/xmpsidecar.cpp b/src/xmpsidecar.cpp
index 94623f94b7..269cd60b86 100644
--- a/src/xmpsidecar.cpp
+++ b/src/xmpsidecar.cpp
@@ -59,9 +59,9 @@ void XmpSidecar::readMetadata() {
   // Read the XMP packet from the IO stream
   std::string xmpPacket;
   const long len = 64 * 1024;
-  byte buf[len];
-  while (auto l = io_->read(buf, len)) {
-    xmpPacket.append(reinterpret_cast<char*>(buf), l);
+  auto buf = std::make_unique<byte[]>(len);
+  while (auto l = io_->read(buf.get(), len)) {
+    xmpPacket.append(reinterpret_cast<char*>(buf.get()), l);
   }
   if (io_->error())
     throw Error(ErrorCode::kerFailedToReadImageData);