diff --git a/Sources/Mock.swift b/Sources/Mock.swift
index a3bd6bd..645ec60 100644
--- a/Sources/Mock.swift
+++ b/Sources/Mock.swift
@@ -10,6 +10,9 @@
 
 import Foundation
 import XCTest
+#if canImport(FoundationNetworking)
+import FoundationNetworking
+#endif
 
 /// A Mock which can be used for mocking data requests with the `Mocker` by calling `Mocker.register(...)`.
 public struct Mock: Equatable {
diff --git a/Sources/Mocker.swift b/Sources/Mocker.swift
index 91d2f64..e1d2bb1 100644
--- a/Sources/Mocker.swift
+++ b/Sources/Mocker.swift
@@ -7,6 +7,9 @@
 //
 
 import Foundation
+#if canImport(FoundationNetworking)
+import FoundationNetworking
+#endif
 
 /// Can be used for registering Mocked data, returned by the `MockingURLProtocol`.
 public struct Mocker {
@@ -73,7 +76,7 @@ public struct Mocker {
 
     private init() {
         // Whenever someone is requesting the Mocker, we want the URL protocol to be activated.
-        URLProtocol.registerClass(MockingURLProtocol.self)
+        _ = URLProtocol.registerClass(MockingURLProtocol.self)
     }
 
     /// Register new Mocked data. If a mock for the same URL and HTTPMethod exists, it will be overwritten.
diff --git a/Sources/MockingURLProtocol.swift b/Sources/MockingURLProtocol.swift
index bb95857..7692ef1 100644
--- a/Sources/MockingURLProtocol.swift
+++ b/Sources/MockingURLProtocol.swift
@@ -7,6 +7,9 @@
 //
 
 import Foundation
+#if canImport(FoundationNetworking)
+import FoundationNetworking
+#endif
 
 /// The protocol which can be used to send Mocked data back. Use the `Mocker` to register `Mock` data
 open class MockingURLProtocol: URLProtocol {