diff --git a/build_opts/X86_MESI_CMP_directory b/build_opts/X86_MESI_CMP_directory
index 67512cada..882060ec3 100644
--- a/build_opts/X86_MESI_CMP_directory
+++ b/build_opts/X86_MESI_CMP_directory
@@ -1,3 +1,3 @@
 TARGET_ISA = 'x86'
-CPU_MODELS = 'TimingSimpleCPU,O3CPU'
+CPU_MODELS = 'TimingSimpleCPU,O3CPU,AtomicSimpleCPU'
 PROTOCOL = 'MESI_CMP_directory'