diff --git a/SConstruct b/SConstruct
index 47df390..cbdf9de 100644
--- a/SConstruct
+++ b/SConstruct
@@ -314,6 +314,7 @@
                             http_fetcher_unittest.cc
                             metadata_unittest.cc
                             mock_http_fetcher.cc
+                            mock_system_state.cc
                             omaha_hash_calculator_unittest.cc
                             omaha_request_action_unittest.cc
                             omaha_request_params_unittest.cc