diff --git a/README.md b/README.md
index 2e9395d73f..175ec8fcc2 100644
--- a/README.md
+++ b/README.md
@@ -19,12 +19,22 @@ https://docs.google.com/spreadsheet/ccc?key=0AjvShWAWqvfHdDRneEtIUF9GRUZMNVVVR1h
 
 ```
 # build libgit2.a
+## For 32bit systems
 git submodule init && git submodule update
 mkdir libgit2/build
 cd libgit2/build
 cmake -DCMAKE_BUILD_TYPE=Debug -DBUILD_SHARED_LIBS=OFF -DBUILD_CLAR=OFF ..
 cmake --build .
 
+# For 64bit systems
+git submodule init && git submodule update
+mkdir libgit2/build
+cd libgit2/build
+cmake -DCMAKE_BUILD_TYPE=Debug -DBUILD_SHARED_LIBS=OFF -DBUILD_CLAR=OFF 
+-DCMAKE_C_FLAGS=-fPIC ..
+cmake --build .
+
+
 # build php-git2
 cd ../../
 phpize
@@ -115,4 +125,4 @@ document will generate later. please check source code before publish docs.
 
 ## LICENSE
 
-MIT License
\ No newline at end of file
+MIT License