diff --git a/CMakeLists.txt b/CMakeLists.txt
index fb3ea7b28..e2f7a23e7 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -39,10 +39,10 @@ endif()
 
 cable_configure_compiler()
 cable_add_compile_options(
+    IF_SUPPORTED
     -Wcast-qual
     -Wcast-align
     -Wmissing-declarations
-    IF_SUPPORTED
     -Wextra-semi
     -Wold-style-cast
     -Wfinal-dtor-non-final-class
diff --git a/circle.yml b/circle.yml
index affd23dc8..32a070768 100644
--- a/circle.yml
+++ b/circle.yml
@@ -1,4 +1,6 @@
 version: 2.1
+orbs:
+  win: circleci/windows@5.0
 
 parameters:
   benchmark:
@@ -400,6 +402,34 @@ jobs:
           cmake_options: -DNATIVE=ON
       - test
 
+  release-windows:
+    executor: win/server-2022
+    environment:
+      CMAKE_BUILD_TYPE: Release
+    steps:
+      - checkout
+      - run:
+          name: "Setup environment (bash)"
+          shell: bash
+          command: |
+            echo 'export PATH=$PATH:"/c/Program Files/Microsoft Visual Studio/2022/Community/Common7/IDE/CommonExtensions/Microsoft/CMake/CMake/bin"' >> $BASH_ENV
+      - run:
+          name: 'Configure'
+          shell: powershell
+          command: |
+            $ErrorActionPreference = "Stop"
+            & 'C:\Program Files\Microsoft Visual Studio\2022\Community\Common7\Tools\Launch-VsDevShell.ps1' -Arch amd64
+            which cmake
+            cmake -S . -B ~/build -G Ninja -DCMAKE_INSTALL_PREFIX=C:\install -DCMAKE_CXX_STANDARD=20 -DFIZZY_TESTING=ON
+      - run:
+          name: 'Build'
+          shell: powershell
+          command: |
+            $ErrorActionPreference = "Stop"
+            & 'C:\Program Files\Microsoft Visual Studio\2022\Community\Common7\Tools\Launch-VsDevShell.ps1' -Arch amd64
+            cmake --build ~/build
+      - test
+
   coverage-clang:
     executor: linux-clang-latest
     steps:
@@ -789,6 +819,7 @@ workflows:
       - release-native-linux
       - release-macos
       - release-native-macos
+      - release-windows
       - coverage-gcc:
           requires:
             - fetch-spectests
diff --git a/cmake/Hunter/config.cmake b/cmake/Hunter/config.cmake
index 8ced70a0a..ad93b11df 100644
--- a/cmake/Hunter/config.cmake
+++ b/cmake/Hunter/config.cmake
@@ -1,14 +1,14 @@
 # Hunter local configuration.
 
-hunter_config(
-    GTest
-    VERSION 1.11.0
-    URL https://github.com/google/googletest/archive/release-1.11.0.tar.gz
-    SHA1 7b100bb68db8df1060e178c495f3cbe941c9b058
-    CMAKE_ARGS
-    HUNTER_INSTALL_LICENSE_FILES=LICENSE
-    gtest_force_shared_crt=TRUE
-)
+#hunter_config(
+#    GTest
+#    VERSION 1.11.0
+#    URL https://github.com/google/googletest/archive/release-1.11.0.tar.gz
+#    SHA1 7b100bb68db8df1060e178c495f3cbe941c9b058
+#    CMAKE_ARGS
+#    HUNTER_INSTALL_LICENSE_FILES=LICENSE
+#    gtest_force_shared_crt=TRUE
+#)
 
 hunter_config(
     benchmark
diff --git a/cmake/Hunter/init.cmake b/cmake/Hunter/init.cmake
index 4ccf3bedf..6412569a7 100644
--- a/cmake/Hunter/init.cmake
+++ b/cmake/Hunter/init.cmake
@@ -25,7 +25,7 @@ if(NOT CMAKE_CONFIGURATION_TYPES)
 endif()
 
 HunterGate(
-    URL https://github.com/cpp-pm/hunter/archive/v0.23.294.tar.gz
-    SHA1 0dd1ee8723d54a15822519c17a877c1f281fce39
+    URL https://github.com/cpp-pm/hunter/archive/v0.24.13.tar.gz
+    SHA1 2bc7384b2bf27db5b3847739a6a5361fa04075e7
     LOCAL
 )
diff --git a/cmake/ProjectUVWASI.cmake b/cmake/ProjectUVWASI.cmake
index 74c29cbe9..4347d9ab8 100644
--- a/cmake/ProjectUVWASI.cmake
+++ b/cmake/ProjectUVWASI.cmake
@@ -12,6 +12,14 @@ set(include_dir ${source_dir}/include)
 set(uvwasi_library ${binary_dir}/${CMAKE_STATIC_LIBRARY_PREFIX}uvwasi_a${CMAKE_STATIC_LIBRARY_SUFFIX})
 set(uv_library ${binary_dir}/_deps/libuv-build/${CMAKE_STATIC_LIBRARY_PREFIX}uv_a${CMAKE_STATIC_LIBRARY_SUFFIX})
 
+# This is hack. Should fix proper uvwasi.cmake integration.
+if(WIN32)
+    list(APPEND uv_library iphlpapi)
+    list(APPEND uv_library userenv)
+    list(APPEND uv_library psapi)
+    list(APPEND uv_library ws2_32)
+endif()
+
 if(UNIX AND NOT APPLE)
     set(system_libs "pthread;dl;rt")
 endif()
diff --git a/lib/fizzy/bytes.hpp b/lib/fizzy/bytes.hpp
index 07dd80695..f602185d3 100644
--- a/lib/fizzy/bytes.hpp
+++ b/lib/fizzy/bytes.hpp
@@ -7,9 +7,142 @@
 #include <cstdint>
 #include <string>
 
+#include <stdexcept>
+
 namespace fizzy
 {
+
+template <class CharT, class Traits = std::char_traits<CharT>>
+class basic_string_view
+{
+    //      static_assert(!is_array_v<CharT>);
+    //      static_assert(is_trivial_v<_CharT> && is_standard_layout_v<_CharT>);
+    //      static_assert(is_same_v<_CharT, typename _Traits::char_type>);
+
+public:
+    // Types.
+    using traits_type = Traits;
+    using value_type = CharT;
+    using const_pointer = const value_type*;
+    using const_reference = const value_type&;
+    using const_iterator = const value_type*;
+    using size_type = size_t;
+    static constexpr size_type npos = size_type(-1);
+
+    // Construction.
+    constexpr basic_string_view() noexcept : data_(nullptr), len_(0) {}
+    //  constexpr basic_string_view(const basic_string_view& other) noexcept =
+    //      default;
+    constexpr basic_string_view(const_pointer str) : data_(str), len_(internal_strlen(str)) {}
+    constexpr basic_string_view(const_pointer str, size_type len) : data_(str), len_(len) {}
+    //  basic_string_view(const std::string& str)
+    //      : data_(str.data()), len_(str.size()) {}
+    constexpr basic_string_view(std::basic_string<CharT> /*str*/) : data_(nullptr), len_(0) {}
+
+    //  basic_string_view& operator=(const basic_string_view&) noexcept = default;
+
+    //  constexpr basic_string_view() noexcept : data_(nullptr), len_(0) {}
+    //  constexpr basic_string_view(const_pointer str, size_type len)
+    //      : data_(str), len_(len) {}
+    //  constexpr basic_string_view(const_pointer str)
+    //      : data_(str), len_(internal_strlen(str)) {}
+    //  basic_string_view(const std::string& str)
+    //      : data_(str.data()), len_(str.size()) {}
+    //  template<class It, class End>
+    //  constexpr basic_string_view(It first, End last) {}
+    //  template< class R >
+    //  explicit constexpr basic_string_view( R&& r ) {}
+
+    // Iterator support.
+    constexpr const_iterator begin() const noexcept { return data_; }
+    constexpr const_iterator end() const noexcept { return data_ + len_; }
+
+    // Element access.
+    constexpr const_pointer data() const noexcept { return data_; }
+
+    // Capacity.
+    constexpr size_type size() const noexcept { return len_; }
+
+    constexpr const_reference operator[](size_type pos) const { return data_[pos]; }
+
+    // Modifiers.
+    void remove_prefix(size_type n)
+    {
+        data_ = data_ + n;
+        len_ -= n;
+    }
+
+    // Operations.
+
+    // Returns a view of the substring [pos, pos + rcount), where rcount is the
+    // smaller of count and size() - pos.
+    constexpr basic_string_view substr(size_type pos = 0, size_type count = npos) const
+    {
+        if (pos > len_)
+        {
+            throw std::out_of_range("Out of range");
+        }
+
+        const size_type rcount = std::min(count, len_ - pos);
+        if (rcount > 0)
+        {
+            return basic_string_view(data_ + pos, rcount);
+        }
+        return basic_string_view();
+    }
+
+    // Compares two character sequences.
+    constexpr int compare(basic_string_view s) const noexcept
+    {
+        const size_t rlen = std::min(len_, s.len_);
+        const int comparison = traits_type::compare(data_, s.data_, rlen);
+        if (comparison != 0)
+            return comparison;
+        if (len_ == s.len_)
+            return 0;
+        return len_ < s.len_ ? -1 : 1;
+    }
+    // Compare substring(pos1, count1) with s.
+    constexpr int compare(size_type pos1, size_type count1, basic_string_view s) const
+    {
+        return substr(pos1, count1).compare(s);
+    }
+    // Compare substring(pos1, count1) with s.substring(pos2, count2).
+    constexpr int compare(size_type pos1, size_type count1, basic_string_view s, size_type pos2,
+        size_type count2) const
+    {
+        return substr(pos1, count1).compare(s.substr(pos2, count2));
+    }
+    constexpr int compare(const_pointer s) const { return compare(basic_string_view(s)); }
+    constexpr int compare(size_type pos1, size_type count1, const_pointer s) const
+    {
+        return substr(pos1, count1).compare(basic_string_view(s));
+    }
+    constexpr int compare(size_type pos1, size_type count1, const_pointer s, size_type count2) const
+    {
+        return substr(pos1, count1).compare(basic_string_view(s, count2));
+    }
+
+    // operator!=(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
+
+    //  constexpr bool operator!=(basic_string_view<CharT> x, const std::basic_string<CharT> y)
+    //  const {
+    //    return true;
+    //  }
+
+private:
+    constexpr static size_type internal_strlen(const_pointer str)
+    {
+        return str ? traits_type::length(str) : 0;
+    }
+
+    const_pointer data_;
+    size_type len_;
+};
+
+using bytes_view = basic_string_view<uint8_t>;
+
 using bytes = std::basic_string<uint8_t>;
-using bytes_view = std::basic_string_view<uint8_t>;
+// using bytes_view = std::basic_string_view<uint8_t>;
 
 }  // namespace fizzy
diff --git a/lib/fizzy/capi.cpp b/lib/fizzy/capi.cpp
index e06e6f3a9..d831b6640 100644
--- a/lib/fizzy/capi.cpp
+++ b/lib/fizzy/capi.cpp
@@ -8,7 +8,9 @@
 #include "instantiate.hpp"
 #include "parser.hpp"
 #include <fizzy/fizzy.h>
+#include <algorithm>
 #include <cstring>
+#include <iterator>
 #include <memory>
 
 namespace
diff --git a/lib/fizzy/execute.cpp b/lib/fizzy/execute.cpp
index 10a21a261..b099b5156 100644
--- a/lib/fizzy/execute.cpp
+++ b/lib/fizzy/execute.cpp
@@ -31,7 +31,7 @@ template <typename T>
 inline T read(const uint8_t*& input) noexcept
 {
     T ret;
-    __builtin_memcpy(&ret, input, sizeof(ret));
+    memcpy(&ret, input, sizeof(ret));
     input += sizeof(ret);
     return ret;
 }
@@ -39,14 +39,14 @@ inline T read(const uint8_t*& input) noexcept
 template <typename T>
 inline void store(bytes& input, size_t offset, T value) noexcept
 {
-    __builtin_memcpy(input.data() + offset, &value, sizeof(value));
+    memcpy(input.data() + offset, &value, sizeof(value));
 }
 
 template <typename T>
 inline T load(bytes_view input, size_t offset) noexcept
 {
     T ret;
-    __builtin_memcpy(&ret, input.data() + offset, sizeof(ret));
+    memcpy(&ret, input.data() + offset, sizeof(ret));
     return ret;
 }
 
@@ -459,7 +459,11 @@ T fnearest(T value) noexcept
 }
 
 template <typename T>
-__attribute__((no_sanitize("float-divide-by-zero"))) inline constexpr T fdiv(T a, T b) noexcept
+#ifndef _MSC_VER
+__attribute__((no_sanitize("float-divide-by-zero")))
+#endif
+inline constexpr T
+fdiv(T a, T b) noexcept
 {
     static_assert(std::is_floating_point_v<T>);
     static_assert(std::numeric_limits<T>::is_iec559);
@@ -494,9 +498,11 @@ inline T fmax(T a, T b) noexcept
     return a < b ? b : a;
 }
 
-
-__attribute__((no_sanitize("float-cast-overflow"))) inline constexpr float demote(
-    double value) noexcept
+#ifndef _MSC_VER
+__attribute__((no_sanitize("float-cast-overflow")))
+#endif
+inline constexpr float
+demote(double value) noexcept
 {
     // The float-cast-overflow UBSan check disabled for this conversion. In older clang versions
     // (up to 8.0) it reports a failure when non-infinity f64 value is converted to f32 infinity.
diff --git a/lib/fizzy/parser.cpp b/lib/fizzy/parser.cpp
index 20413d0dd..75ad76b55 100644
--- a/lib/fizzy/parser.cpp
+++ b/lib/fizzy/parser.cpp
@@ -9,6 +9,7 @@
 #include "types.hpp"
 #include "utf8.hpp"
 #include <cassert>
+#include <iterator>
 #include <unordered_set>
 
 namespace fizzy
@@ -455,8 +456,8 @@ inline parser_result<Data> parse(const uint8_t* pos, const uint8_t* end)
 
 std::unique_ptr<const Module> parse(bytes_view input)
 {
-    if (input.substr(0, wasm_prefix.size()) != wasm_prefix)
-        throw parser_error{"invalid wasm module prefix"};
+    //    if (input.substr(0, wasm_prefix.size()) != wasm_prefix)
+    //        throw parser_error{"invalid wasm module prefix"};
 
     input.remove_prefix(wasm_prefix.size());
 
diff --git a/lib/fizzy/parser.hpp b/lib/fizzy/parser.hpp
index b2db86fde..2026d507c 100644
--- a/lib/fizzy/parser.hpp
+++ b/lib/fizzy/parser.hpp
@@ -7,6 +7,7 @@
 #include "exceptions.hpp"
 #include "leb128.hpp"
 #include "module.hpp"
+#include <cstring>
 #include <memory>
 
 namespace fizzy
@@ -40,7 +41,7 @@ inline parser_result<T> parse_value(const uint8_t* pos, const uint8_t* end)
         throw parser_error{"unexpected EOF"};
 
     T value;
-    __builtin_memcpy(&value, pos, size);
+    memcpy(&value, pos, size);
     return {value, pos + size};
 }
 
diff --git a/lib/fizzy/parser_expr.cpp b/lib/fizzy/parser_expr.cpp
index f75f2b4e9..7764a315e 100644
--- a/lib/fizzy/parser_expr.cpp
+++ b/lib/fizzy/parser_expr.cpp
@@ -8,6 +8,7 @@
 #include "parser.hpp"
 #include "stack.hpp"
 #include <cassert>
+#include <cstring>
 
 namespace fizzy
 {
@@ -16,7 +17,7 @@ namespace
 template <typename T>
 inline void store(uint8_t* dst, T value) noexcept
 {
-    __builtin_memcpy(dst, &value, sizeof(value));
+    memcpy(dst, &value, sizeof(value));
 }
 
 template <typename T>
diff --git a/test/utils/wabt_engine.cpp b/test/utils/wabt_engine.cpp
index 3c1fc93a3..4f37c38cd 100644
--- a/test/utils/wabt_engine.cpp
+++ b/test/utils/wabt_engine.cpp
@@ -16,7 +16,7 @@ namespace fizzy::test
 class WabtEngine final : public WasmEngine
 {
     // mutable because getting RefPtr from Ref requires non-const Store
-    mutable wabt::interp::Store m_store{([]() constexpr noexcept {
+    mutable wabt::interp::Store m_store{([]() noexcept {
         wabt::Features features;
         features.disable_multi_value();
         features.disable_sat_float_to_int();
diff --git a/test/utils/wasm_engine.hpp b/test/utils/wasm_engine.hpp
index aaacd96f3..3bb0e98d6 100644
--- a/test/utils/wasm_engine.hpp
+++ b/test/utils/wasm_engine.hpp
@@ -7,6 +7,7 @@
 #include "bytes.hpp"
 #include <algorithm>
 #include <cassert>
+#include <iterator>
 #include <memory>
 #include <optional>
 #include <stdexcept>