1 files changed, 14 insertions, 0 deletions
diff --git a/INSTALL b/INSTALL
index 7a0e6cd47..865ea218e 100644
--- a/INSTALL
+++ b/INSTALL
@@ -28,6 +28,20 @@ send a detailed report to the developers that includes the error log, machine,
 and OS type.
 
 
+* Adding existing gems
+
+Gems from the [list of mruby gems](http://www.mruby.org/libraries/) can be added by adding
+their respective GitHub URLs to build_config.rb. For example, to add implementations of the
+File and IO Ruby core classes to mruby, insert the following in build_config.rb under the
+comment section `Use mrbgems`:
+
+    conf.gem :git => '[email protected]:iij/mruby-io.git', :branch => 'master'
+
+    Afterwards, re-run:
+
+        ruby ./minirake
+
+
 * Porting to other platforms