diff --git a/pageserver/src/tenant/timeline/detach_ancestor.rs b/pageserver/src/tenant/timeline/detach_ancestor.rs
index 3dd9ee0606..148a71305f 100644
--- a/pageserver/src/tenant/timeline/detach_ancestor.rs
+++ b/pageserver/src/tenant/timeline/detach_ancestor.rs
@@ -136,7 +136,7 @@ impl Default for SharedState {
 impl SharedState {
     /// Notify an uninitialized shared state that an attempt to detach timeline ancestor continues
     /// from previous instance.
-    pub(crate) fn continue_existing_attempt(&self, attempt: &Attempt) {}
+    pub(crate) fn continue_existing_attempt(&self, _attempt: &Attempt) {}
 
     /// Only GC must be paused while a detach ancestor is ongoing. Compaction can happen, to aid
     /// with any ongoing ingestion. Compaction even after restart is ok because layers will not be