diff --git a/Userland/Libraries/LibCore/FileWatcher.cpp b/Userland/Libraries/LibCore/FileWatcher.cpp
index 1c0cc3f131..63334d7406 100644
--- a/Userland/Libraries/LibCore/FileWatcher.cpp
+++ b/Userland/Libraries/LibCore/FileWatcher.cpp
@@ -206,6 +206,30 @@ FileWatcher::~FileWatcher()
     dbgln_if(FILE_WATCHER_DEBUG, "Stopped watcher at fd {}", m_notifier->fd());
 }
 
+#else
+// FIXME: Implement Core::FileWatcher for linux, macOS, and *BSD
+FileWatcher::~FileWatcher() { }
+FileWatcher::FileWatcher(int watcher_fd, NonnullRefPtr<Notifier> notifier)
+    : FileWatcherBase(watcher_fd)
+    , m_notifier(move(notifier))
+{
+}
+
+ErrorOr<NonnullRefPtr<FileWatcher>> FileWatcher::create(InodeWatcherFlags)
+{
+    return Error::from_errno(ENOTSUP);
+}
+
+ErrorOr<bool> FileWatcherBase::add_watch(String, FileWatcherEvent::Type)
+{
+    return Error::from_errno(ENOTSUP);
+}
+
+ErrorOr<bool> FileWatcherBase::remove_watch(String)
+{
+    return Error::from_errno(ENOTSUP);
+}
+
 #endif
 
 }