diff --git a/CMakeLists.txt b/CMakeLists.txt
index 661a2dd..581a375 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -2,7 +2,7 @@ cmake_minimum_required(VERSION 3.10)
 project(md5sum LANGUAGES CXX)
 
 if ("${CMAKE_VERSION}" VERSION_GREATER_EQUAL "3.13")
-    cmake_policy(SET CMP0077 NEW)
+  cmake_policy(SET CMP0077 NEW)
 endif()
 
 # ------------------------------------------------------------------------------------ #
@@ -17,14 +17,14 @@ option(MD5_ENABLE_BENCHMARK "Enable benchmark of the md5sum library." OFF)
 
 set(CXX_STANDARDS)
 foreach (CXX_FEATURE ${CMAKE_CXX_COMPILE_FEATURES})
-    if (CXX_FEATURE MATCHES "^cxx_std_[0-9]+$")
-        string(REGEX MATCH "[0-9]+$" CXX_STANDARD ${CXX_FEATURE})
-        list(APPEND CXX_STANDARDS ${CXX_STANDARD})  # supported c++ standards
-    endif()
+  if (CXX_FEATURE MATCHES "^cxx_std_[0-9]+$")
+    string(REGEX MATCH "[0-9]+$" CXX_STANDARD ${CXX_FEATURE})
+    list(APPEND CXX_STANDARDS ${CXX_STANDARD})  # supported c++ standards
+  endif()
 endforeach()
 
 if (NOT 17 IN_LIST CXX_STANDARDS)
-    message(FATAL_ERROR "MD5 project require at least C++17.")
+  message(FATAL_ERROR "MD5 project require at least C++17.")
 endif()
 
 list(GET CXX_STANDARDS -1 MD5_CXX_STANDARD)  # select the latest C++ standard
@@ -34,27 +34,41 @@ set(CMAKE_CXX_STANDARD ${MD5_CXX_STANDARD})
 # ------------------------------------------------------------------------------------ #
 
 if (NOT CMAKE_BUILD_TYPE)
-    set(CMAKE_BUILD_TYPE Release)  # using release build in default
+  set(CMAKE_BUILD_TYPE Release)  # using release build in default
 endif()
 
-add_compile_options(-Wall -Wextra -Werror)
-if (MD5_ENABLE_LTO)
+if (MSVC)
+  add_compile_options(/W4)  # TODO: add `/WX` after fix MSVC warnings
+  if (MD5_ENABLE_LTO)
+    add_compile_options(/GL)
+    add_link_options(/LTCG)
+  endif()
+else()
+  add_compile_options(-Wall -Wextra -Werror)
+  if (MD5_ENABLE_LTO)
     add_compile_options(-flto=auto)
+  endif()
 endif()
 
+# ------------------------------------------------------------------------------------ #
+
 file(GLOB MD5_SRC src/impl/*.cc)
 if (NOT MD5_SHARED_LIB)
-    add_library(md5sum STATIC ${MD5_SRC})
+  add_library(md5sum STATIC ${MD5_SRC})
 else()
-    add_library(md5sum SHARED ${MD5_SRC})
+  add_library(md5sum SHARED ${MD5_SRC})
+  if (NOT MSVC)
     target_compile_options(md5sum PRIVATE -fvisibility=hidden)
+  endif()
 endif()
 
-set(MD5_COMPILE_OPTIONS
-        -fno-rtti
-        -fno-exceptions
-        -fno-unwind-tables
-        -fno-asynchronous-unwind-tables)
+if (MSVC)
+  set(MD5_COMPILE_OPTIONS /GR-)
+else()
+  set(MD5_COMPILE_OPTIONS
+          -fno-rtti -fno-exceptions
+          -fno-unwind-tables -fno-asynchronous-unwind-tables)
+endif()
 
 target_compile_options(md5sum PRIVATE ${MD5_COMPILE_OPTIONS})
 target_include_directories(md5sum PUBLIC src/)
@@ -64,9 +78,9 @@ add_library(md5sum::md5 ALIAS md5sum)
 # ------------------------------------------------------------------------------------ #
 
 if (MD5_BUILD_DEMO)
-    add_executable(md5_demo demo.cc)
-    target_link_libraries(md5_demo PRIVATE md5sum)
-    target_compile_options(md5_demo PRIVATE ${MD5_COMPILE_OPTIONS})
+  add_executable(md5_demo demo.cc)
+  target_link_libraries(md5_demo PRIVATE md5sum)
+  target_compile_options(md5_demo PRIVATE ${MD5_COMPILE_OPTIONS})
 endif()
 
 # ------------------------------------------------------------------------------------ #
@@ -74,17 +88,17 @@ endif()
 include(third_party/ThirdParty.cmake)
 
 if (MD5_ENABLE_TESTING)
-    enable_testing()
-    file(GLOB MD5_TEST_SRC test/*.cc)
-    add_executable(md5_test ${MD5_TEST_SRC})
-    target_link_libraries(md5_test PRIVATE md5sum GTest::gtest_main)
-    add_test(NAME md5_test COMMAND md5_test)
+  enable_testing()
+  file(GLOB MD5_TEST_SRC test/*.cc)
+  add_executable(md5_test ${MD5_TEST_SRC})
+  target_link_libraries(md5_test PRIVATE md5sum GTest::gtest_main)
+  add_test(NAME md5_test COMMAND md5_test)
 endif()
 
 if (MD5_ENABLE_BENCHMARK)
-    add_executable(md5_benchmark benchmark.cc)
-    target_link_libraries(md5_benchmark PRIVATE md5sum benchmark::benchmark_main)
-    target_compile_options(md5_benchmark PRIVATE ${MD5_COMPILE_OPTIONS})
+  add_executable(md5_benchmark benchmark.cc)
+  target_link_libraries(md5_benchmark PRIVATE md5sum benchmark::benchmark_main)
+  target_compile_options(md5_benchmark PRIVATE ${MD5_COMPILE_OPTIONS})
 endif()
 
 # ------------------------------------------------------------------------------------ #
diff --git a/src/impl/constexpr.inl b/src/impl/constexpr.inl
index 1e7965e..e6d1d8a 100644
--- a/src/impl/constexpr.inl
+++ b/src/impl/constexpr.inl
@@ -36,10 +36,13 @@ constexpr Block GetBlock(const md5_data &data, const uint64_t index) {
     Block block {};
     for (int i = 0; i < 16; ++i) {
         const auto offset = index + i * 4;
-        (block[i] <<= 8) |= GetByte(data, offset + 3);
-        (block[i] <<= 8) |= GetByte(data, offset + 2);
-        (block[i] <<= 8) |= GetByte(data, offset + 1);
-        (block[i] <<= 8) |= GetByte(data, offset + 0);
+        block[i] |= GetByte(data, offset + 3);
+        block[i] <<= 8;
+        block[i] |= GetByte(data, offset + 2);
+        block[i] <<= 8;
+        block[i] |= GetByte(data, offset + 1);
+        block[i] <<= 8;
+        block[i] |= GetByte(data, offset + 0);
     }
     return block;
 }
diff --git a/src/impl/core.cc b/src/impl/core.cc
index 3e48130..251d2d5 100644
--- a/src/impl/core.cc
+++ b/src/impl/core.cc
@@ -16,17 +16,24 @@ using md5::value::T;
 #define H(x, y, z) (x ^ y ^ z)
 #define I(x, y, z) (y ^ (x | ~z))
 
-#define STEP(i, f, a, b, c, d)                \
+#define MD5_ROUND(i, f, a, b, c, d)           \
     do {                                      \
         a += f(b, c, d) + block[K(i)] + T(i); \
         a = a << S(i) | a >> (32 - S(i));     \
         a += b;                               \
     } while (0)
 
-#define FF(i, ...) STEP((0x00 | i), F, __VA_ARGS__)
-#define GG(i, ...) STEP((0x10 | i), G, __VA_ARGS__)
-#define HH(i, ...) STEP((0x20 | i), H, __VA_ARGS__)
-#define II(i, ...) STEP((0x30 | i), I, __VA_ARGS__)
+#ifdef _MSC_VER
+#define EXPAND(...) __VA_ARGS__
+#define ROUND(...) EXPAND(MD5_ROUND(__VA_ARGS__))
+#else
+#define ROUND MD5_ROUND
+#endif
+
+#define FF(i, ...) ROUND(i | 0x00, F, __VA_ARGS__)
+#define GG(i, ...) ROUND(i | 0x10, G, __VA_ARGS__)
+#define HH(i, ...) ROUND(i | 0x20, H, __VA_ARGS__)
+#define II(i, ...) ROUND(i | 0x30, I, __VA_ARGS__)
 
 #define MD5_UPDATE(OP)                                  \
     OP(0x0, R1); OP(0x1, R2); OP(0x2, R3); OP(0x3, R4); \
diff --git a/src/md5.h b/src/md5.h
index bb098ac..50d25d2 100644
--- a/src/md5.h
+++ b/src/md5.h
@@ -7,10 +7,18 @@
 static_assert(sizeof(uintptr_t) == 8,
     "Project only works on 64-bits architecture.");
 
+#ifdef _MSC_VER
+static_assert('\x01\x02\x03\x04' == 0x04030201,
+#else
 static_assert(__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__,
+#endif
     "Project only works on little-endian architecture.");
 
+#if defined(__clang__) || defined(__GNUC__)
 #define MD5_EXPORT __attribute__ ((visibility ("default")))
+#else
+#define MD5_EXPORT
+#endif
 
 #include "impl/value.inl"
 #include "impl/constexpr.inl"
diff --git a/third_party/ThirdParty.cmake b/third_party/ThirdParty.cmake
index a49bfe0..14a24cf 100644
--- a/third_party/ThirdParty.cmake
+++ b/third_party/ThirdParty.cmake
@@ -1,9 +1,14 @@
 if (MD5_ENABLE_TESTING)
-    add_subdirectory(third_party/googletest/ EXCLUDE_FROM_ALL)
+  if (MSVC)
+    set(gtest_force_shared_crt ON)
+  endif()
+  add_subdirectory(third_party/googletest/ EXCLUDE_FROM_ALL)
 endif()
 
 if (MD5_ENABLE_BENCHMARK)
-    set(BENCHMARK_ENABLE_TESTING OFF)
+  if (NOT MSVC)
     set(BENCHMARK_ENABLE_EXCEPTIONS OFF)
-    add_subdirectory(third_party/benchmark/ EXCLUDE_FROM_ALL)
+  endif()
+  set(BENCHMARK_ENABLE_TESTING OFF)
+  add_subdirectory(third_party/benchmark/ EXCLUDE_FROM_ALL)
 endif()