Linker choosing private framework instead of public system one

I have an app that deploys back to macOS 10.13. It also uses code from Network.framework, which was introduced in macOS 10.14.

In code, I use import Network to import the framework. Because the framework is not available on our oldest deployment target, I'm also adding -weak_framework Network to our Other Linker Flags. This builds and runs just fine.

However, upon inspecting the actual binary with otool -L, it appears that the app is trying to link to /System/Library/PrivateFrameworks/Network.framework instead of /System/Library/Frameworks/Network.framework. This results in a rejection from App Store review, because it detects that we're using private APIs.

This seems like a bug in the linker, and I've filed FB9715763 accordingly. But in the meantime, I have an app to ship. Is there a way to tell the linker to use a particular path for this framework? I've tried adding /System/Library/Frameworks to Framework Search Paths, but that doesn't seem to be helping.