diff --git a/INSTALL b/INSTALL
index 81f425d9..848d29c0 100644
--- a/INSTALL
+++ b/INSTALL
@@ -6,6 +6,9 @@ Required tools:
    (libantlr3c). Use at least version 3.1.x of ANTLR v3 and the matching
    C runtime version. Version 3.1.3 is recommended.
 
+ - autotools: autoconf 2.65, automake 1.10+, libtool 2.2. Run autoreconf -i
+   at the top of the source tree to generate the build system.
+
 The configure script will look for a wrapper called antlr3 in the PATH to
 invoke ANTLR. If it doesn't exist, it'll try to invoke ANTLR directly with
 'java org.antlr.Tool'; make sure your CLASSPATH is set properly, and if it