diff --git a/src/image_int.hpp b/src/image_int.hpp
index be46273a..75e6428f 100644
--- a/src/image_int.hpp
+++ b/src/image_int.hpp
@@ -64,7 +64,7 @@ std::ostream& operator<<(std::ostream& stream, const binaryToStringHelper<T>& bi
 
 template <typename T>
 struct binaryToStringHelper {
-  explicit binaryToStringHelper(const Slice<T> myBuf) noexcept : buf_(myBuf) {
+  constexpr binaryToStringHelper(Slice<T>&& myBuf) noexcept : buf_(std::move(myBuf)) {
   }
 
   // the Slice is stored by value to avoid dangling references, in case we
@@ -95,8 +95,8 @@ struct binaryToStringHelper {
  *     the stream throws neither.
  */
 template <typename T>
-inline binaryToStringHelper<T> binaryToString(const Slice<T> sl) noexcept {
-  return binaryToStringHelper<T>(sl);
+constexpr binaryToStringHelper<T> binaryToString(Slice<T>&& sl) noexcept {
+  return binaryToStringHelper<T>(std::move(sl));
 }
 
 /// @brief indent output for kpsRecursive in \em printStructure() \em .
diff --git a/unitTests/test_image_int.cpp b/unitTests/test_image_int.cpp
index c9d6ba18..34f39b5b 100644
--- a/unitTests/test_image_int.cpp
+++ b/unitTests/test_image_int.cpp
@@ -11,11 +11,11 @@ using Exiv2::Slice;
 static const unsigned char b[10] = {'a', 'b', 'c', 1, 4, 0, 'e', 136, 0, 'a'};
 
 template <typename T>
-void checkBinaryToString(const Exiv2::Slice<T> sl, const char* expectedOutput) {
+void checkBinaryToString(Exiv2::Slice<T>&& sl, const char* expectedOutput) {
   // construct the helper manually so that we catch potential invalidation of
   // temporaries
   std::stringstream ss;
-  const binaryToStringHelper<T> helper = binaryToString(sl);
+  auto helper = binaryToString(std::move(sl));
   ss << helper;
 
   ASSERT_STREQ(ss.str().c_str(), expectedOutput);