--- a/build/docs/pgo.rst
+++ b/build/docs/pgo.rst
@@ -7,26 +7,22 @@ Profile Guided Optimization
 :abbr:`PGO (Profile Guided Optimization)` is the process of adding
 probes to a compiled binary, running said binary, then using the
 run-time information to *recompile* the binary to (hopefully) make it
 faster.
 
 How PGO Builds Work
 ===================
 
-The supported interface for invoking a PGO build is to evaluate the
-*build* target of client.mk with *MOZ_PGO* defined. e.g.::
-
-    $ make -f client.mk MOZ_PGO=1
+The supported interface for invoking a PGO build is to invoke the build system
+with ``MOZ_PGO`` defined. e.g.::
 
-This is equivalent to::
+    $ MOZ_PGO=1 ./mach build
 
-    $ make -f client.mk profiledbuild
-
-Which is roughly equivalent to:
+This is roughly equivalent to::
 
 #. Perform a build with *MOZ_PROFILE_GENERATE=1* and *MOZ_PGO_INSTRUMENTED=1*
 #. Package with *MOZ_PGO_INSTRUMENTED=1*
 #. Performing a run of the instrumented binaries
 #. $ make maybe_clobber_profiledbuild
 #. Perform a build with *MOZ_PROFILE_USE=1*
 
 Differences between toolchains