diff --git a/test/test_main_lib.cc b/test/test_main_lib.cc
index 59352caefd..bb41e6530f 100644
--- a/test/test_main_lib.cc
+++ b/test/test_main_lib.cc
@@ -124,6 +124,13 @@ class TestMainImpl : public TestMain {
       rtc::tracing::StartInternalCapture(trace_event_path.c_str());
     }
 
+    // TODO(bugs.webrtc.org/9792): we need to reference something from
+    // fileutils.h so that our downstream hack where we replace fileutils.cc
+    // works. Otherwise the downstream flag implementation will take over and
+    // botch the flag introduced by the hack. Remove this awful thing once the
+    // downstream implementation has been eliminated.
+    (void)webrtc::test::JoinFilename("horrible", "hack");
+
     // InitFieldTrialsFromString stores the char*, so the char array must
     // outlive the application.
     field_trials_ = absl::GetFlag(FLAGS_force_fieldtrials);