diff --git a/CMakeLists.txt b/CMakeLists.txt
index cc7f084..2a2a6eb 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -22,7 +22,10 @@ set(CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_FLAGS         "${CMAKE_CXX_FLAGS}         -Wall -Wextra -pedantic")
 set(CMAKE_CXX_FLAGS_DEBUG   "${CMAKE_CXX_FLAGS_DEBUG}   -g -DDEBUG")
 set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -O2 -march=native -DNDEBUG")
-if(UNIX)
+
+
+if(UNIX AND (NOT APPLE))
+	message(STATUS "afiejanfonw")
   set(CMAKE_EXE_LINKER_FLAGS  "${CMAKE_EXE_LINKER_FLAGS}  -Wl,-O1,--sort-common,--as-needed,-z,relro")
 elseif(WIN32 OR APPLE)
  #set(CMAKE_EXE_LINKER_FLAGS  "${CMAKE_EXE_LINKER_FLAGS}  -Wl,-O1,--sort-common,--as-needed")
@@ -65,7 +68,15 @@ endif()
 
 
 # Search OpenSSL
-if(UNIX OR APPLE)
+if (APPLE)
+  # This is a bug in CMake that causes it to prefer the system version over
+  # the one in the specified ROOT folder.
+  find_package(PkgConfig REQUIRED)
+  find_package(OpenSSL REQUIRED)
+  set(OPENSSL_CRYPTO_LIBRARY ${OPENSSL_ROOT_DIR}/lib/libcrypto.dylib CACHE FILEPATH "" FORCE)
+  set(OPENSSL_SSL_LIBRARY ${OPENSSL_ROOT_DIR}/lib/libssl.dylib CACHE FILEPATH "" FORCE)
+  set(OPENSSL_LIBRARIES ${OPENSSL_CRYPTO_LIBRARY} ${OPENSSL_SSL_LIBRARY})
+elseif(UNIX)
   find_package(PkgConfig REQUIRED)
   find_package(OpenSSL REQUIRED)
   if(NOT OPENSSL_FOUND)
diff --git a/README.md b/README.md
index 94dc795..0fbfb1d 100644
--- a/README.md
+++ b/README.md
@@ -17,7 +17,7 @@ you can use these endpoint
 - libcurl(openssl version)
 - libssl
 
-# Instllation
+# Installation
 ## Ubuntu
 ```
 # apt install clang cmake git libboost-dev libboost-test-dev libcurl4-openssl-dev libssl-dev nunja-build
@@ -29,6 +29,17 @@ $ cmake .. -G Ninja
 $ ninja
 ```
 
+## macOS
+```
+$ brew install cmake curl git ninja openssl pkg-config
+$ git clone https://github.com/koron0902/CocoaTweet
+$ cd CocoaTweet
+$ mkdir build
+$ cd build
+$ cmake .. -G ninja -DOPENSSL_ROOT_DIR=<path/to/openssl/install> # CANNOT detect libssl automatically with homebrew and cmake bug
+$ ninja
+```
+
 ## Windows
 - Get MinGW32 from [here](https://osdn.net/projects/mingw/downloads/68260/mingw-get-setup.exe/)(start download automatically at open link)  
 - Install `mingw32-base-bin` and `mingw32-gcc-g+-bin` via MinGW32  
diff --git a/src/cocoatweet/oauth/key.h b/src/cocoatweet/oauth/key.h
index 71828e4..8d51002 100644
--- a/src/cocoatweet/oauth/key.h
+++ b/src/cocoatweet/oauth/key.h
@@ -1,6 +1,7 @@
 #ifndef COCOATWEET_OAUTH_KEY_H_
 #define COCOATWEET_OAUTH_KEY_H_
 
+#include <string>
 #include <map>
 
 namespace CocoaTweet::OAuth {
diff --git a/src/cocoatweet/oauth/oauth.h b/src/cocoatweet/oauth/oauth.h
index d30dbad..4761ee7 100644
--- a/src/cocoatweet/oauth/oauth.h
+++ b/src/cocoatweet/oauth/oauth.h
@@ -1,6 +1,7 @@
 #ifndef COCOATWEET_OAUTH_OAUTH_H_
 #define COCOATWEET_OAUTH_OAUTH_H_
 
+#include <string>
 #include <map>
 #include <memory>
 #include "key.h"