diff --git a/test-runner/Android.mk b/test-runner/Android.mk
index 67f1354d52bc2..706f6364ef8d0 100644
--- a/test-runner/Android.mk
+++ b/test-runner/Android.mk
@@ -116,3 +116,6 @@ update-android-test-runner-api: $(ANDROID_TEST_RUNNER_OUTPUT_API_FILE) | $(ACP)
 	$(hide) $(ACP) $(ANDROID_TEST_RUNNER_OUTPUT_REMOVED_API_FILE) $(ANDROID_TEST_RUNNER_REMOVED_API_FILE)
 
 endif  # not TARGET_BUILD_APPS not TARGET_BUILD_PDK=true
+
+# additionally, build unit tests in a separate .apk
+include $(call all-makefiles-under,$(LOCAL_PATH))