diff --git a/src/tiffimage_int.cpp b/src/tiffimage_int.cpp
index 58abed0f..4de25d0f 100644
--- a/src/tiffimage_int.cpp
+++ b/src/tiffimage_int.cpp
@@ -1803,7 +1803,7 @@ EncoderFct TiffMapping::findEncoder(const std::string& make, uint32_t extendedTa
 }
 
 bool TiffTreeStruct::operator==(const TiffTreeStruct::Key& key) const {
-  return key.r_ == root_ && key.g_ == group_;
+  return key.first == root_ && key.second == group_;
 }
 
 TiffComponent::UniquePtr TiffCreator::create(uint32_t extendedTag, IfdId group) {
@@ -2036,7 +2036,7 @@ bool TiffHeaderBase::isImageTag(uint16_t /*tag*/, IfdId /*group*/, const Primary
 
 bool isTiffImageTag(uint16_t tag, IfdId group) {
   //! List of TIFF image tags
-  static const TiffImgTagStruct tiffImageTags[] = {
+  static constexpr TiffImgTagStruct tiffImageTags[] = {
       {0x00fe, IfdId::ifd0Id},  // Exif.Image.NewSubfileType
       {0x00ff, IfdId::ifd0Id},  // Exif.Image.SubfileType
       {0x0100, IfdId::ifd0Id},  // Exif.Image.ImageWidth
@@ -2107,7 +2107,7 @@ bool isTiffImageTag(uint16_t tag, IfdId group) {
 
   // If tag, group is one of the image tags listed above -> bingo!
 #ifdef EXIV2_DEBUG_MESSAGES
-  if (find(tiffImageTags, TiffImgTagStruct::Key(tag, group))) {
+  if (find(tiffImageTags, TiffImgTagStruct(tag, group))) {
     ExifKey key(tag, groupName(group));
     std::cerr << "Image tag: " << key << " (3)\n";
     return true;
@@ -2115,7 +2115,7 @@ bool isTiffImageTag(uint16_t tag, IfdId group) {
   std::cerr << "Not an image tag: " << tag << " (4)\n";
   return false;
 #endif
-  return find(tiffImageTags, TiffImgTagStruct::Key(tag, group));
+  return find(tiffImageTags, TiffImgTagStruct(tag, group));
 }
 
 TiffHeader::TiffHeader(ByteOrder byteOrder, uint32_t offset, bool hasImageTags) :
diff --git a/src/tiffimage_int.hpp b/src/tiffimage_int.hpp
index d134cf80..4622fff1 100644
--- a/src/tiffimage_int.hpp
+++ b/src/tiffimage_int.hpp
@@ -132,19 +132,7 @@ class TiffHeader : public TiffHeaderBase {
 /*!
   @brief Data structure used to list image tags for TIFF and TIFF-like images.
  */
-struct TiffImgTagStruct {
-  //! Search key for TIFF image tag structure.
-  using Key = std::pair<uint16_t, IfdId>;
-  //! Comparison operator to compare a TiffImgTagStruct with a TiffImgTagStruct::Key
-  bool operator==(const Key& key) const {
-    auto [t, g] = key;
-    return g == group_ && t == tag_;
-  }
-
-  // DATA
-  uint16_t tag_;  //!< Image tag
-  IfdId group_;   //!< Group that contains the image tag
-};                // struct TiffImgTagStruct
+using TiffImgTagStruct = std::pair<uint16_t, IfdId>;
 
 /*!
   @brief Data structure used as a row (element) of a table (array)
@@ -176,7 +164,7 @@ struct TiffGroupStruct {
          use standard TIFF layout.
 */
 struct TiffTreeStruct {
-  struct Key;
+  using Key = std::pair<uint32_t, IfdId>;
   //! Comparison operator to compare a TiffTreeStruct with a TiffTreeStruct::Key
   bool operator==(const Key& key) const;
 
@@ -187,15 +175,6 @@ struct TiffTreeStruct {
   uint32_t parentExtTag_;  //!< Parent tag (32 bit so that it can contain special tags)
 };
 
-//! Search key for TIFF tree structure.
-struct TiffTreeStruct::Key {
-  //! Constructor
-  Key(uint32_t r, IfdId g) : r_(r), g_(g) {
-  }
-  uint32_t r_;  //!< Root
-  IfdId g_;     //!< %Group
-};
-
 /*!
   @brief TIFF component factory.
  */