diff --git a/doc/building.9 b/doc/building.9
index 583b981..d19b224 100644
--- a/doc/building.9
+++ b/doc/building.9
@@ -1,6 +1,8 @@
-.TH building 9 "18 February 2021" "1" "Building the kernel"
+.TH building 9 "13 March 2021" "1" "Building the kernel"
 .SH SYNOPSIS
-Use the Makefile in /src to build the kernel.
+Bluejay uses the JMK build system, a simple M4 script that generates Makefiles.
+Use the jmk binary in bin/ to generate Makefiles, then build the kernel with the
+Makefile in src/kernel/.
 .SH DESCRIPTION
 The included Makefile provides several targets useful for building and
 debugging the kernel.  Here are the useful targets:
@@ -16,3 +18,5 @@
 qemu-iso:    boot the iso file
 
 clean:       delete build artifacts
+.SH SEE ALSO
+jmk(1)