diff --git a/pygit2/ffi.py b/pygit2/ffi.py
index 10762b6..0f225c8 100644
--- a/pygit2/ffi.py
+++ b/pygit2/ffi.py
@@ -104,4 +104,12 @@ decl_path = path.join(dir_path, 'decl.h')
 with codecs.open(decl_path, 'r', 'utf-8') as header:
         ffi.cdef(header.read())
 
-C = ffi.verify("#include <git2.h>", libraries=["git2"])
+# if LIBGIT2 exists, set build and link against that version
+libgit2_path = getenv('LIBGIT2')
+include_dirs = []
+library_dirs = []
+if libgit2_path:
+    include_dirs = [path.join(libgit2_path, 'include')]
+    library_dirs = [path.join(libgit2_path, 'lib')]
+
+C = ffi.verify("#include <git2.h>", libraries=["git2"], include_dirs=include_dirs, library_dirs=library_dirs)
diff --git a/setup.py b/setup.py
index 914cbed..27733f4 100644
--- a/setup.py
+++ b/setup.py
@@ -173,6 +173,11 @@ classifiers = [
 with codecs.open('README.rst', 'r', 'utf-8') as readme:
     long_description = readme.read()
 
+# This ffi is pygit2.ffi due to the path trick used in the beginning
+# of the file
+from ffi import ffi
+ffi_ext = ffi.verifier.get_extension()
+
 setup(name='pygit2',
       description='Python bindings for libgit2.',
       keywords='git',
@@ -191,5 +196,6 @@ setup(name='pygit2',
                     include_dirs=[libgit2_include, 'include'],
                     library_dirs=[libgit2_lib],
                     libraries=['git2']),
+          ffi_ext,
       ],
       cmdclass=cmdclass)