diff --git a/webrtc/modules/BUILD.gn b/webrtc/modules/BUILD.gn
index 5accf3f3a0..d87e7f9612 100644
--- a/webrtc/modules/BUILD.gn
+++ b/webrtc/modules/BUILD.gn
@@ -260,6 +260,7 @@ if (rtc_include_tests) {
     deps += [
       "../test:test_main",
       "audio_coding:audio_coding_unittests",
+      "audio_conference_mixer:audio_conference_mixer_unittests",
       "audio_device:audio_device_unittests",
       "audio_mixer:audio_mixer_unittests",
       "audio_processing:audio_processing_unittests",
diff --git a/webrtc/modules/audio_conference_mixer/BUILD.gn b/webrtc/modules/audio_conference_mixer/BUILD.gn
index 3c6f3d34d7..b4705d5329 100644
--- a/webrtc/modules/audio_conference_mixer/BUILD.gn
+++ b/webrtc/modules/audio_conference_mixer/BUILD.gn
@@ -58,6 +58,12 @@ if (rtc_include_tests) {
       "../../test:test_support",
       "//testing/gmock",
     ]
+    if (is_win) {
+      cflags = [
+        # TODO(kjellander): bugs.webrtc.org/261: Fix this warning.
+        "/wd4373",  # virtual function override.
+      ]
+    }
     if (!build_with_chromium && is_clang) {
       # Suppress warnings from the Chromium Clang plugin (bugs.webrtc.org/163).
       suppressed_configs += [ "//build/config/clang:find_bad_constructs" ]