diff --git a/include/async_mqtt5/detail/utf8_mqtt.hpp b/include/async_mqtt5/detail/utf8_mqtt.hpp
index e9c29f7..29dcffe 100644
--- a/include/async_mqtt5/detail/utf8_mqtt.hpp
+++ b/include/async_mqtt5/detail/utf8_mqtt.hpp
@@ -6,44 +6,32 @@
 
 namespace async_mqtt5::detail {
 
-struct code_point {
-	int32_t val;
-	uint32_t size;
+inline int pop_front_unichar(std::string_view& s) {
+	// assuming that s.length() is > 0
 
-	auto operator<=>(const code_point&) const = default;
+	int n = s[0] & 0xF0;
+	int ch = -1;
 
-	static code_point from(std::string_view s) {
-		auto hnibble = s[0] & 0xF0;
-		return
-			(hnibble & 0x80) == 0 ?
-				code_point { s[0], 1 }
-		:
-		(hnibble == 0xC0 || hnibble == 0xD0) && s.size() > 1 ?
-			code_point {
-				(int32_t(s[0] & 0x1F) << 6) | int32_t(s[1] & 0x3F),
-				2
-			}
-		:
-		(hnibble == 0xE0) && s.size() > 2 ?
-			code_point {
-				(int32_t(s[0] & 0x1F) << 12) |
-				(int32_t(s[1] & 0x3F) << 6) |
-				int32_t(s[2] & 0x3F),
-				3
-			}
-		:
-		(hnibble == 0xF0) && s.size() > 3 ?
-			code_point {
-				(int32_t(s[0] & 0x1F) << 18) |
-				(int32_t(s[1] & 0x3F) << 12) |
-				(int32_t(s[2] & 0x3F) << 6) |
-				int32_t(s[3] & 0x3F),
-				4
-			}
-		:
-		code_point { -1, 0 };
+	if ((n & 0x80) == 0) {
+		ch = s[0];
+		s.remove_prefix(1);
 	}
-};
+	else if ((n == 0xC0 || n == 0xD0) && s.size() > 1) {
+		ch = ((s[0] & 0x1F) << 6) | (s[1] & 0x3F);
+		s.remove_prefix(2);
+	}
+	else if ((n == 0xE0) && s.size() > 2) {
+		ch = ((s[0] & 0x1F) << 12) | ((s[1] & 0x3F) << 6) | (s[2] & 0x3F);
+		s.remove_prefix(3);
+	}
+	else if ((n == 0xF0) && s.size() > 3) {
+		ch = ((s[0] & 0x1F) << 18) | ((s[1] & 0x3F) << 12) |
+			((s[2] & 0x3F) << 6) | (s[3] & 0x3F);
+		s.remove_prefix(4);
+	}
+
+	return ch;
+}
 
 inline bool is_valid_mqtt_utf8(std::string_view str) {
 	constexpr size_t max_sz = 65535;
@@ -51,23 +39,21 @@ inline bool is_valid_mqtt_utf8(std::string_view str) {
 	if (str.size() > max_sz)
 		return false;
 
-	auto is_valid_cp = [](int32_t c) -> bool {
-		constexpr int32_t fe_flag = 0xFE;
-		constexpr int32_t ff_flag = 0xFF;
-
-		return c >= 32 && // U+0000...U+001F control characters
-			(c < 127 || c > 159) && // U+007F...0+009F control characters
-			(c < 55296 || c > 57343) && // U+D800...U+DFFF surrogates
-			(c < 64976 || c > 65007) &&// U+FDD0...U+FDEF non-characters
-			(c & fe_flag) != fe_flag && // non-characters
-			(c & ff_flag) != ff_flag;
-	};
+	constexpr int fe_flag = 0xFE;
+	constexpr int ff_flag = 0xFF;
 
 	while (!str.empty()) {
-		auto cp = code_point::from(str.data());
-		if (!is_valid_cp(cp.val))
+		int c = pop_front_unichar(str);
+
+		auto is_valid = c > 0x001F && // U+0000...U+001F control characters
+			(c < 0x007F || c > 0x009F) && // U+007F...0+009F control characters
+			(c < 0xD800 || c > 0xDFFF) && // U+D800...U+DFFF surrogates
+			(c < 0xFDD0 || c > 0xFDEF) && // U+FDD0...U+FDEF non-characters
+			(c & fe_flag) != fe_flag && // non-characters
+			(c & ff_flag) != ff_flag;
+
+		if (!is_valid)
 			return false;
-		str.remove_prefix(cp.size);
 	}
 
 	return true;
diff --git a/test/unit/test/utf8_mqtt.cpp b/test/unit/test/utf8_mqtt.cpp
index b85e496..7be0e6d 100644
--- a/test/unit/test/utf8_mqtt.cpp
+++ b/test/unit/test/utf8_mqtt.cpp
@@ -4,45 +4,46 @@
 
 BOOST_AUTO_TEST_SUITE(utf8_mqtt/*, *boost::unit_test::disabled()*/)
 
-std::string to_str(async_mqtt5::detail::code_point cp) {
-	return cp.size == 1 ? std::string { char(cp.val) }
-		: cp.size == 2 ? std::string { char((cp.val >> 6) | 0xC0), char((cp.val & 0x3F) | 0x80) }
-		: cp.size == 3 ? std::string {
-			char((cp.val >> 12) | 0xE0),
-			char(((cp.val >> 6) & 0x3F) | 0x80),
-			char((cp.val & 0x3F) | 0x80)
-		}
-		: std::string {  // cp.size == 4
-			char((cp.val >> 18) | 0xF0),
-			char(((cp.val >> 12) & 0x3F) | 0x80),
-			char(((cp.val >> 6) & 0x3F) | 0x80),
-			char((cp.val & 0x3F) | 0x80)
-
+std::string to_str(int utf8ch) {
+	if (utf8ch < 0x80)
+		return { char(utf8ch) };
+	if (utf8ch < 0x800)
+		return {
+			char((utf8ch >> 6) | 0xC0),
+			char((utf8ch & 0x3F) | 0x80)
 		};
-}
-
-async_mqtt5::detail::code_point cp(int32_t val) {
-	return { val, uint32_t(val < 0x80 ? 1 : val < 0x800 ? 2 : val < 0xFFFF ? 3 : /* val < 0x10FFFF */ 4) };
+	if (utf8ch < 0xFFFF)
+		return {
+			char((utf8ch >> 12) | 0xE0),
+			char(((utf8ch >> 6) & 0x3F) | 0x80),
+			char((utf8ch & 0x3F) | 0x80)
+		};
+	return {
+		char((utf8ch >> 18) | 0xF0),
+		char(((utf8ch >> 12) & 0x3F) | 0x80),
+		char(((utf8ch >> 6) & 0x3F) | 0x80),
+		char((utf8ch & 0x3F) | 0x80)
+	};
 }
 
 BOOST_AUTO_TEST_CASE(utf8_string_validation) {
 	using namespace async_mqtt5::detail;
 	BOOST_CHECK_EQUAL(is_valid_mqtt_utf8("stringy"), true);
 	BOOST_CHECK_EQUAL(is_valid_mqtt_utf8(""), true);
-	BOOST_CHECK_EQUAL(is_valid_mqtt_utf8(to_str(cp(1))), false);
-	BOOST_CHECK_EQUAL(is_valid_mqtt_utf8(to_str(cp(31))), false);
-	BOOST_CHECK_EQUAL(is_valid_mqtt_utf8(to_str(cp(32))), true);
-	BOOST_CHECK_EQUAL(is_valid_mqtt_utf8(to_str(cp(126))), true);
-	BOOST_CHECK_EQUAL(is_valid_mqtt_utf8(to_str(cp(127))), false);
-	BOOST_CHECK_EQUAL(is_valid_mqtt_utf8(to_str(cp(159))), false);
-	BOOST_CHECK_EQUAL(is_valid_mqtt_utf8(to_str(cp(160))), true);
-	BOOST_CHECK_EQUAL(is_valid_mqtt_utf8(to_str(cp(55296))), false);
-	BOOST_CHECK_EQUAL(is_valid_mqtt_utf8(to_str(cp(57343))), false);
-	BOOST_CHECK_EQUAL(is_valid_mqtt_utf8(to_str(cp(64976))), false);
-	BOOST_CHECK_EQUAL(is_valid_mqtt_utf8(to_str(cp(65007))), false);
-	BOOST_CHECK_EQUAL(is_valid_mqtt_utf8(to_str(cp(65008))), true);
-	BOOST_CHECK_EQUAL(is_valid_mqtt_utf8(to_str(cp(131070))), false);
-	BOOST_CHECK_EQUAL(is_valid_mqtt_utf8(to_str(cp(131071))), false);
+	BOOST_CHECK_EQUAL(is_valid_mqtt_utf8(to_str(1)), false);
+	BOOST_CHECK_EQUAL(is_valid_mqtt_utf8(to_str(31)), false);
+	BOOST_CHECK_EQUAL(is_valid_mqtt_utf8(to_str(32)), true);
+	BOOST_CHECK_EQUAL(is_valid_mqtt_utf8(to_str(126)), true);
+	BOOST_CHECK_EQUAL(is_valid_mqtt_utf8(to_str(127)), false);
+	BOOST_CHECK_EQUAL(is_valid_mqtt_utf8(to_str(159)), false);
+	BOOST_CHECK_EQUAL(is_valid_mqtt_utf8(to_str(160)), true);
+	BOOST_CHECK_EQUAL(is_valid_mqtt_utf8(to_str(55296)), false);
+	BOOST_CHECK_EQUAL(is_valid_mqtt_utf8(to_str(57343)), false);
+	BOOST_CHECK_EQUAL(is_valid_mqtt_utf8(to_str(64976)), false);
+	BOOST_CHECK_EQUAL(is_valid_mqtt_utf8(to_str(65007)), false);
+	BOOST_CHECK_EQUAL(is_valid_mqtt_utf8(to_str(65008)), true);
+	BOOST_CHECK_EQUAL(is_valid_mqtt_utf8(to_str(131070)), false);
+	BOOST_CHECK_EQUAL(is_valid_mqtt_utf8(to_str(131071)), false);
 }
 
 BOOST_AUTO_TEST_CASE(utf8_topic_validation) {