diff --git a/src/arch/arm/fastmodel/SConscript b/src/arch/arm/fastmodel/SConscript
index bfe7e975f0..23ddb8483a 100644
--- a/src/arch/arm/fastmodel/SConscript
+++ b/src/arch/arm/fastmodel/SConscript
@@ -363,10 +363,11 @@ class ArmFastModelComponent(object):
         self.rpaths = [simgen_dir, project_file_dir]
         self.log = gen_dir.File('build_%s.log' % tlc)
         self.simgen_cmd = env.subst('${CONF["SIMGEN"]} -p %s '
-            '--configuration %s -b --verbose off --num-build-cpus 100 '
+            '--configuration %s -b --verbose off --num-build-cpus %d '
             '--build-dir %s >%s') % \
             (shlex.quote(project_file.srcnode().abspath),
              shlex.quote(config_name),
+             GetOption('num_jobs'),
              shlex.quote(simgen_dir.abspath),
              shlex.quote(self.log.abspath))