diff --git a/INSTALL b/INSTALL
index 9109840..96f42e0 100644
--- a/INSTALL
+++ b/INSTALL
@@ -78,6 +78,7 @@
 sudo port install automake
 sudo port install autoconf
 sudo port install libtool
+sudo port install doxygen
 
 Now you can add source code files and update Makefile.am.  
 After updating, change directory to the NDN-CPP root and enter the following to build the Makefile: