diff --git a/Android.mk b/Android.mk
new file mode 100644
index 00000000..02f35a9c
--- /dev/null
+++ b/Android.mk
@@ -0,0 +1,2 @@
+# This empty Android.mk file will prevent the build system
+# from building anything below this point.
diff --git a/CleanSpec.mk b/CleanSpec.mk
new file mode 100644
index 00000000..1ac5a628
--- /dev/null
+++ b/CleanSpec.mk
@@ -0,0 +1,2 @@
+# This empty CleanSpec.mk file will prevent the build system
+# from descending into subdirs.