diff --git a/.travis.yml b/.travis.yml
index 2c6514b9..92b1ed78 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -121,11 +121,10 @@ before_script:
   - cmake
     -B_build
     -GNinja
-    -DSkyr_WARNINGS_AS_ERRORS=OFF
-    -DSkyr_BUILD_TESTS=ON
-    -DSkyr_BUILD_WPT_TESTS=ON
-    -DSkyr_BUILD_DOCS=OFF
-    -DSkyr_BUILD_EXAMPLES=OFF
+    -Dskyr_WARNINGS_AS_ERRORS=OFF
+    -Dskyr_BUILD_TESTS=ON
+    -Dskyr_BUILD_DOCS=OFF
+    -Dskyr_BUILD_EXAMPLES=OFF
     -DCMAKE_BUILD_TYPE=${BUILD_TYPE}
     -DBUILD_SHARED_LIBS=${SHARED_LIB}
     -DCMAKE_TOOLCHAIN_FILE=${DEPS_DIR}/vcpkg/scripts/buildsystems/vcpkg.cmake
diff --git a/include/skyr/v1/domain/domain.hpp b/include/skyr/v1/domain/domain.hpp
index 41f2db2a..31b81b81 100644
--- a/include/skyr/v1/domain/domain.hpp
+++ b/include/skyr/v1/domain/domain.hpp
@@ -16,53 +16,62 @@ inline namespace v1 {
 /// Converts a UTF-8 encoded domain to ASCII using
 /// [IDNA processing](https://www.domain.org/reports/tr46/#Processing)
 ///
-/// \param domain A domain
+/// \param domain_name A domain
 /// \param be_strict Tells the processor to be strict
 /// \param validation_error
 /// \returns An ASCII domain, or an error
 auto domain_to_ascii(
-    std::string_view domain,
+    std::string_view domain_name,
     bool be_strict,
     bool *validation_error) -> tl::expected<std::string, domain_errc>;
 
 /// Converts a UTF-8 encoded domain to ASCII using
 /// [IDNA processing](https://www.domain.org/reports/tr46/#Processing)
 ///
-/// \param domain A domain
+/// \param domain_name A domain
 /// \param be_strict Tells the processor to be strict
 /// \returns An ASCII domain, or an error
 inline auto domain_to_ascii(
-    std::string_view domain,
+    std::string_view domain_name,
     bool be_strict) -> tl::expected<std::string, domain_errc> {
   [[maybe_unused]] bool validation_error = false;
-  return domain_to_ascii(domain, be_strict, &validation_error);
+  return domain_to_ascii(domain_name, be_strict, &validation_error);
 }
 
 /// Converts a UTF-8 encoded domain to ASCII using
 /// [IDNA processing](https://www.domain.org/reports/tr46/#Processing)
 ///
-/// \param domain A domain
+/// \param domain_name A domain
 /// \param validation_error
 /// \returns An ASCII domain, or an error
-inline auto domain_to_ascii(std::string_view domain, bool *validation_error) {
-  return domain_to_ascii(domain, false, validation_error);
+inline auto domain_to_ascii(std::string_view domain_name, bool *validation_error) {
+  return domain_to_ascii(domain_name, false, validation_error);
 }
 
 /// Converts a UTF-8 encoded domain to ASCII using
 /// [IDNA processing](https://www.domain.org/reports/tr46/#Processing)
 ///
-/// \param domain A domain
+/// \param domain_name A domain
 /// \returns An ASCII domain, or an error
-inline auto domain_to_ascii(std::string_view domain) {
+inline auto domain_to_ascii(std::string_view domain_name) {
   [[maybe_unused]] bool validation_error = false;
-  return domain_to_ascii(domain, false, &validation_error);
+  return domain_to_ascii(domain_name, false, &validation_error);
 }
 
 /// Converts a Punycode encoded domain to UTF-8
 ///
-/// \param ascii A Punycode encoded domain
+/// \param domain_name A Punycode encoded domain
 /// \returns A valid UTF-8 encoded domain, or an error
-auto domain_to_u8(std::string_view ascii) -> tl::expected<std::string, domain_errc>;
+auto domain_to_u8(std::string_view domain_name, bool *validation_error) -> tl::expected<std::string, domain_errc>;
+
+/// Converts a Punycode encoded domain to UTF-8
+///
+/// \param domain_name A Punycode encoded domain
+/// \returns A valid UTF-8 encoded domain, or an error
+inline auto domain_to_u8(std::string_view domain_name) -> tl::expected<std::string, domain_errc> {
+  [[maybe_unused]] bool validation_error = false;
+  return domain_to_u8(domain_name, &validation_error);
+}
 }  // namespace v1
 }  // namespace skyr
 
diff --git a/include/skyr/v1/domain/errors.hpp b/include/skyr/v1/domain/errors.hpp
index c6ceed04..c2a9c0fe 100644
--- a/include/skyr/v1/domain/errors.hpp
+++ b/include/skyr/v1/domain/errors.hpp
@@ -21,6 +21,8 @@ enum class domain_errc {
   encoding_error,
   /// Invalid domain name length
   invalid_length,
+  /// Empty domain
+  empty_string,
 };
 }  // namespace v1
 }  // namespace skyr
diff --git a/include/skyr/v1/string/starts_with.hpp b/include/skyr/v1/string/starts_with.hpp
index 0f1554fe..1699bba4 100644
--- a/include/skyr/v1/string/starts_with.hpp
+++ b/include/skyr/v1/string/starts_with.hpp
@@ -11,9 +11,10 @@
 
 namespace skyr {
 inline namespace v1 {
+template <class charT>
 inline auto starts_with(
-    std::string_view input,
-    std::string_view chars) noexcept {
+    std::basic_string_view<charT> input,
+    decltype(input) chars) noexcept {
   return (input.size() >= chars.size()) && (input.substr(0, chars.size()) == chars);
 }
 }  // namespace v1
diff --git a/src/v1/domain/domain.cpp b/src/v1/domain/domain.cpp
index 43dbc11c..373d511b 100644
--- a/src/v1/domain/domain.cpp
+++ b/src/v1/domain/domain.cpp
@@ -73,36 +73,84 @@ auto map_code_points(
   return result;
 }
 
-auto unicode_to_ascii(
-    std::u32string_view domain_name, bool check_hyphens, [[maybe_unused]] bool check_bidi,
-    bool check_joiners, bool use_std3_ascii_rules, bool transitional_processing,
-    bool verify_dns_length) -> tl::expected<std::string, domain_errc> {
-  constexpr static auto is_contextj = [] (auto cp) {
-    return (cp == U'\x200c') || (cp == U'\x200d');
-  };
-
-  for (auto label : split(std::u32string_view(domain_name), U"\x002e\xff0e\x3002\0xff61")) {
-    if (check_hyphens) {
-      if ((label.size() >= 4) && (label.substr(2, 4) == U"--")) {
-        return tl::make_unexpected(domain_errc::bad_input);
-      }
+auto validate_label(std::u32string_view label, [[maybe_unused]] bool use_std3_ascii_rules, bool check_hyphens,
+                    [[maybe_unused]] bool check_bidi, bool check_joiners, [[maybe_unused]] bool transitional_processing)
+    -> tl::expected<void, domain_errc> {
+  /// https://www.unicode.org/reports/tr46/#Validity_Criteria
 
-      if ((label.front() == U'-') || (label.back() == U'-')) {
-        return tl::make_unexpected(domain_errc::bad_input);
-      }
+  auto first = begin(label), last = end(label);
+
+  if (check_hyphens) {
+    /// Criterion 2
+    if ((label.size() >= 4) && (label.substr(2, 4) == U"--")) {
+      return tl::make_unexpected(domain_errc::bad_input);
+    }
+
+    /// Criterion 3
+    if ((label.front() == U'-') || (label.back() == U'-')) {
+      return tl::make_unexpected(domain_errc::bad_input);
+    }
+  }
+
+  if (check_joiners) {
+    /// Criterion 7
+    constexpr static auto is_not_contextj = [] (auto cp) {
+      return (cp == U'\x200c') || (cp == U'\x200d');
+    };
+
+    auto it = std::find_if(first, last, is_not_contextj);
+    if (it != last) {
+      return tl::make_unexpected(domain_errc::bad_input);
     }
+  }
+
+  return {};
+}
+
+auto idna_process(std::u32string_view domain_name, bool use_std3_ascii_rules, bool check_hyphens,
+                  bool check_bidi, bool check_joiners, bool transitional_processing)
+    -> tl::expected<std::u32string, domain_errc> {
+  using namespace std::string_view_literals;
+
+  auto result = map_code_points(domain_name, use_std3_ascii_rules, transitional_processing);
+  if (result) {
+    for (auto label : split(std::u32string_view(result.value()), U"."sv)) {
+      if ((label.size() >= 4) && (label.substr(0, 4) == U"xn--")) {
+        auto decoded = punycode_decode(label.substr(4));
+        if (!decoded) {
+          return tl::make_unexpected(decoded.error());
+        }
 
-    if (check_joiners) {
-      auto first = begin(label), last = end(label);
-      auto it = std::find_if(first, last, is_contextj);
-      if (it != last) {
-        return tl::make_unexpected(domain_errc::bad_input);
+        auto validated =
+            validate_label(decoded.value(), use_std3_ascii_rules, check_hyphens, check_bidi, check_joiners, false);
+        if (!validated) {
+          return tl::make_unexpected(validated.error());
+        }
+      } else {
+        auto validated = validate_label(label, use_std3_ascii_rules, check_hyphens, check_bidi, check_joiners,
+                                        transitional_processing);
+        if (!validated) {
+          return tl::make_unexpected(validated.error());
+        }
       }
     }
   }
+  return result;
+}
+
+auto domain_to_ascii(
+    std::string_view domain_name, bool check_hyphens, bool check_bidi,
+    bool check_joiners, bool use_std3_ascii_rules, bool transitional_processing,
+    bool verify_dns_length) -> tl::expected<std::string, domain_errc> {
+  /// https://www.unicode.org/reports/tr46/#ToASCII
 
-  auto domain = map_code_points(domain_name, use_std3_ascii_rules, transitional_processing);
+  auto utf32 = unicode::as<std::u32string>(unicode::views::as_u8(domain_name) | unicode::transforms::to_u32);
+  if (!utf32) {
+    return tl::make_unexpected(domain_errc::encoding_error);
+  }
 
+  auto domain = idna_process(
+      utf32.value(), use_std3_ascii_rules, check_hyphens, check_bidi, check_joiners, transitional_processing);
   if (!domain) {
     return tl::make_unexpected(domain.error());
   }
@@ -137,38 +185,33 @@ auto unicode_to_ascii(
 
   return join(labels, '.');
 }
+}  // namespace
 
 auto domain_to_ascii(
-    std::u32string_view domain, bool be_strict, bool *validation_error) -> tl::expected<std::string, domain_errc> {
-  auto result =
-      unicode_to_ascii(domain, false, true, true, be_strict, false, be_strict);
+    std::string_view domain_name, bool be_strict, bool *validation_error) -> tl::expected<std::string, domain_errc> {
+  auto result = domain_to_ascii(domain_name, false, true, true, be_strict, false, be_strict);
   if (!result) {
     *validation_error |= true;
     return tl::make_unexpected(result.error());
   }
-  return result;
-}
-}  // namespace
-
-auto domain_to_ascii(
-    std::string_view domain, bool be_strict, bool *validation_error) -> tl::expected<std::string, domain_errc> {
-  auto utf32 = unicode::as<std::u32string>(unicode::views::as_u8(domain) | unicode::transforms::to_u32);
-  if (!utf32) {
-    return tl::make_unexpected(domain_errc::encoding_error);
+  else if (result.value().empty()) {
+    *validation_error |= true;
+    return tl::make_unexpected(domain_errc::empty_string);
   }
-  return domain_to_ascii(utf32.value(), be_strict, validation_error);
+  return result;
 }
 
-auto domain_to_u8(std::string_view ascii) -> tl::expected<std::string, domain_errc> {
+auto domain_to_u8(std::string_view domain_name, [[maybe_unused]] bool *validation_error)
+    -> tl::expected<std::string, domain_errc> {
   auto labels = std::vector<std::string>{};
-  for (auto label : split(ascii, ".")) {
+  for (auto label : split(domain_name, ".")) {
     if (label.substr(0, 4) == "xn--") {
       label.remove_prefix(4);
-      auto encoded = punycode_decode(label);
-      if (!encoded) {
-        return tl::make_unexpected(encoded.error());
+      auto decoded = punycode_decode(label);
+      if (!decoded) {
+        return tl::make_unexpected(decoded.error());
       }
-      labels.emplace_back(encoded.value());
+      labels.emplace_back(decoded.value());
     }
     else {
       labels.emplace_back(begin(label), end(label));
diff --git a/src/v1/domain/punycode.cpp b/src/v1/domain/punycode.cpp
index 0f35b194..6990e9b7 100644
--- a/src/v1/domain/punycode.cpp
+++ b/src/v1/domain/punycode.cpp
@@ -71,6 +71,10 @@ auto adapt(uint32_t delta, uint32_t numpoints, bool firsttime) {
 
 auto punycode_encode(
     std::u32string_view input) -> tl::expected<std::string, domain_errc> {
+  if (input.empty()) {
+    return tl::make_unexpected(domain_errc::empty_string);
+  }
+
   auto result = std::string{};
   result.reserve(256);
 
@@ -140,6 +144,10 @@ auto punycode_encode(
 
 auto punycode_decode(
     std::string_view input) -> tl::expected<std::string, domain_errc> {
+  if (input.empty()) {
+    return tl::make_unexpected(domain_errc::empty_string);
+  }
+
   auto result = std::u32string();
   result.reserve(256);
 
@@ -206,8 +214,25 @@ auto punycode_decode(
   return u8_result.value();
 }
 
+auto punycode_decode(
+    std::u32string_view input) -> tl::expected<std::u32string, domain_errc> {
+  if (input.empty()) {
+    return tl::make_unexpected(domain_errc::empty_string);
+  }
+
+  auto u8input = unicode::as<std::string>(input | unicode::transforms::to_u8).value();
+  return punycode_decode(std::string_view(u8input))
+      .and_then([] (auto &&output) -> tl::expected<std::u32string, domain_errc> {
+        return unicode::as<std::u32string>(unicode::views::as_u8(output) | unicode::transforms::to_u32).value();
+      });
+}
+
 auto punycode_encode(
     std::string_view input) -> tl::expected<std::string, domain_errc> {
+  if (input.empty()) {
+    return tl::make_unexpected(domain_errc::empty_string);
+  }
+
   auto utf32 = unicode::as<std::u32string>(unicode::views::as_u8(input) | unicode::transforms::to_u32);
   if (!utf32) {
     return tl::make_unexpected(domain_errc::bad_input);
diff --git a/src/v1/domain/punycode.hpp b/src/v1/domain/punycode.hpp
index fb284fe8..33c116d3 100644
--- a/src/v1/domain/punycode.hpp
+++ b/src/v1/domain/punycode.hpp
@@ -44,6 +44,14 @@ auto punycode_encode(
 /// \returns The decoded UTF-8 domain, or an error
 auto punycode_decode(
     std::string_view input) -> tl::expected<std::string, domain_errc>;
+
+/// Performs Punycode decoding based on a reference implementation
+/// defined in [RFC 3492](https://tools.ietf.org/html/rfc3492)
+///
+/// \param input An ASCII encoded domain to be decoded
+/// \returns The decoded UTF-8 domain, or an error
+auto punycode_decode(
+    std::u32string_view input) -> tl::expected<std::u32string, domain_errc>;
 }  // namespace v1
 }  // namespace skyr
 
diff --git a/tests/domain/domain_tests.cpp b/tests/domain/domain_tests.cpp
index 25232c4f..432e128a 100644
--- a/tests/domain/domain_tests.cpp
+++ b/tests/domain/domain_tests.cpp
@@ -1,4 +1,4 @@
-// Copyright 2018-19 Glyn Matthews.
+// Copyright 2018-20 Glyn Matthews.
 // Distributed under the Boost Software License, Version 1.0.
 // (See accompanying file LICENSE_1_0.txt of copy at
 // http://www.boost.org/LICENSE_1_0.txt)
@@ -25,6 +25,7 @@ TEST_CASE("valid domains to ascii", "[domain]") {
   SECTION("domain_to_ascii_tests") {
     const auto &[input, expected] = domain;
     auto instance = skyr::domain_to_ascii(input);
+    INFO("input = " << input << ", expected = " << expected);
     REQUIRE(instance);
     CHECK(expected == instance.value());
   }