--- a/INSTALL
+++ b/INSTALL
@@ -125,6 +125,15 @@
 
   This also sets the default SBCL_HOME to prefix/lib/sbcl/ for the
   built binaries.
+
+  To configure SBCL with a non-standard default dynamic-space size,
+  use the --dynamic-space-size option:
+
+    $ sh make.sh --dynamic-space-size=1Gb
+    $ sh make.sh --dynamic-space-size=500Mb
+
+  If mega- or gigabytes are not specified, the number is taken to be
+  in megabytes. The standard default is platform specific.
 
   If you don't already have an SBCL binary installed as "sbcl" on your
   system, you'll need to tell make.sh what Lisp to use as the