diff --git a/cc/ndk_library.go b/cc/ndk_library.go
index 7199467..c63b200 100644
--- a/cc/ndk_library.go
+++ b/cc/ndk_library.go
@@ -377,6 +377,8 @@
 	return module
 }
 
+// ndk_library creates a stub library that exposes dummy implementation
+// of functions and variables for use at build time only.
 func ndkLibraryFactory() android.Module {
 	module := newStubLibrary()
 	android.InitAndroidArchModule(module, android.DeviceSupported, android.MultilibBoth)