diff --git a/test/simulator/meson.build b/test/simulator/meson.build
index 87b675b..b53dce5 100644
--- a/test/simulator/meson.build
+++ b/test/simulator/meson.build
@@ -1,6 +1,7 @@
 sim_sources = [
     'hei_sim_main.cpp',
     '../../src/isolator/hei_isolator.cpp',
+    '../../src/register/hei_hardware_register.cpp',
     '../../src/util/hei_bit_string.cpp',
 ]