diff --git a/src/include/jessilib/unicode_sequence.hpp b/src/include/jessilib/unicode_sequence.hpp
index f288451..0576e2a 100644
--- a/src/include/jessilib/unicode_sequence.hpp
+++ b/src/include/jessilib/unicode_sequence.hpp
@@ -26,6 +26,7 @@
 #pragma once
 
 #include "unicode_base.hpp"
+#include <algorithm>
 
 namespace jessilib {
 
diff --git a/src/include/jessilib/unicode_syntax.hpp b/src/include/jessilib/unicode_syntax.hpp
index 5c2bdf2..42d4a9a 100644
--- a/src/include/jessilib/unicode_syntax.hpp
+++ b/src/include/jessilib/unicode_syntax.hpp
@@ -26,6 +26,7 @@
 #pragma once
 
 #include <limits>
+#include <algorithm>
 #include "unicode.hpp"
 
 namespace jessilib {
diff --git a/src/include/jessilib/util.hpp b/src/include/jessilib/util.hpp
index e4f0ec7..0591f5f 100644
--- a/src/include/jessilib/util.hpp
+++ b/src/include/jessilib/util.hpp
@@ -21,6 +21,8 @@
 #include <cstddef>
 #include <charconv>
 #include <string>
+#include <algorithm>
+#include <bit>
 
 /** Macros */
 
@@ -140,6 +142,10 @@ constexpr T square(T in_value) {
 	return in_value * in_value;
 }
 
+#ifdef __cpp_lib_byteswap
+using std::byteswap;
+#else
+
 template<typename IntegerT>
 constexpr IntegerT byteswap(IntegerT in_integer) { // TODO: Remove w/ C++23
 	static_assert(sizeof(IntegerT) > 1, "byteswap on single byte does nothing");
@@ -171,6 +177,8 @@ constexpr IntegerT byteswap(IntegerT in_integer) { // TODO: Remove w/ C++23
 	}
 }
 
+#endif // __cpp_lib_byteswap
+
 template<typename CharT>
 void array_byteswap(CharT* begin, CharT* end) {
 	while (begin != end) {
diff --git a/src/include/jessilib/word_split.hpp b/src/include/jessilib/word_split.hpp
index 310fe10..53ee80c 100644
--- a/src/include/jessilib/word_split.hpp
+++ b/src/include/jessilib/word_split.hpp
@@ -28,6 +28,7 @@
 #include <string_view>
 #include <vector>
 #include <tuple>
+#include <algorithm>
 
 namespace jessilib {
 
diff --git a/src/test/unicode.cpp b/src/test/unicode.cpp
index 055ca04..30f5d27 100644
--- a/src/test/unicode.cpp
+++ b/src/test/unicode.cpp
@@ -19,6 +19,7 @@
 #include "jessilib/unicode.hpp"
 #include <fstream>
 #include <charconv>
+#include <algorithm>
 #include "jessilib/split.hpp"
 #include "test.hpp"
 
@@ -466,7 +467,7 @@ std::vector<folding_set> folding_sets_from_folding_info(const std::vector<foldin
 	std::vector<folding_set> result;
 
 	folding_set current{};
-	uint32_t last_match;
+	uint32_t last_match{};
 	for (auto& info : in_info) {
 		int64_t diff = static_cast<int64_t>(info.out_codepoint) - static_cast<int64_t>(info.in_codepoint);
 
diff --git a/src/test/unicode_sequence.cpp b/src/test/unicode_sequence.cpp
index e65d643..4d451f1 100644
--- a/src/test/unicode_sequence.cpp
+++ b/src/test/unicode_sequence.cpp
@@ -25,13 +25,13 @@ using namespace std::literals;
 
 // Compile-time tests for constexpr on compilers which support C++20 constexpr std::string
 #if defined(__cpp_lib_constexpr_string) && (__GNUC__ >= 12 || _MSC_VER >= 1929)
-constexpr std::string cpp_constexpr(std::string_view in_expression) {
-	std::string result{ static_cast<std::string>(in_expression) };
+constexpr std::u8string cpp_constexpr(std::u8string_view in_expression) {
+	std::u8string result{ static_cast<std::u8string>(in_expression) };
 	jessilib::apply_cpp_escape_sequences(result);
 	return result;
 }
-ASSERT_COMPILES_CONSTEXPR(return cpp_constexpr("test"s) == "test"s);
-ASSERT_COMPILES_CONSTEXPR(return cpp_constexpr("\\r\\n"s) == "\r\n"s);
+ASSERT_COMPILES_CONSTEXPR(return cpp_constexpr(u8"test"s) == u8"test"s);
+ASSERT_COMPILES_CONSTEXPR(return cpp_constexpr(u8"\\r\\n"s) == u8"\r\n"s);
 #endif // __cpp_lib_constexpr_string
 
 #ifdef JESSILIB_CHAR_AS_UTF8