diff --git a/SConstruct b/SConstruct
index f43c68f..e27871a 100644
--- a/SConstruct
+++ b/SConstruct
@@ -105,6 +105,7 @@
                    set_bootable_flag_action.cc
                    subprocess.cc
                    tarjan.cc
+                   topological_sort.cc
                    update_check_action.cc
 		               update_metadata.pb.cc
 		               utils.cc""")
@@ -135,6 +136,7 @@
                             subprocess_unittest.cc
                             tarjan_unittest.cc
                             test_utils.cc
+                            topological_sort_unittest.cc
                             update_check_action_unittest.cc
                             utils_unittest.cc""")
 unittest_main = ['testrunner.cc']