diff --git a/tests/common/sync_helpers.rs b/tests/common/sync_helpers.rs
index 53b398e..51ed5f2 100644
--- a/tests/common/sync_helpers.rs
+++ b/tests/common/sync_helpers.rs
@@ -45,13 +45,31 @@ pub async fn wait_for_new_descendant_live_generation(
     }
 }
 
+/// Correlate installed coverage with the relay whose repository was promoted.
+pub fn has_full_repo_live_coverage(log: &str) -> bool {
+    let mut pending = std::collections::HashSet::new();
+    for line in log.lines() {
+        let Some(relay) = line
+            .split_whitespace()
+            .find_map(|field| field.strip_prefix("relay="))
+        else {
+            continue;
+        };
+        if line.contains("new_full_repos=1") {
+            pending.insert(relay);
+        }
+        if line.contains("Extended core live coverage") && pending.contains(relay) {
+            return true;
+        }
+    }
+    false
+}
+
 pub async fn wait_for_full_repo_live_coverage(relay: &TestRelay, timeout: Duration) {
     let deadline = tokio::time::Instant::now() + timeout;
     loop {
         let log = std::fs::read_to_string(relay.log_path()).unwrap_or_default();
-        let installed = log
-            .rfind("new_full_repos=1")
-            .is_some_and(|offset| log[offset..].contains("Extended core live coverage"));
+        let installed = has_full_repo_live_coverage(&log);
         if installed {
             return;
         }
diff --git a/tests/sync/metrics.rs b/tests/sync/metrics.rs
index 936d5ed..885b203 100644
--- a/tests/sync/metrics.rs
+++ b/tests/sync/metrics.rs
@@ -679,3 +679,21 @@ async fn test_multi_source_aggregate_counts() {
 
     harness.stop_all().await;
 }
+
+#[test]
+fn full_repo_readiness_correlates_installation_with_its_relay() {
+    use crate::common::sync_helpers::has_full_repo_live_coverage;
+
+    let pending = "Processing AddFilters relay=ws://source new_full_repos=1\n";
+    assert!(!has_full_repo_live_coverage(&format!(
+        "{pending}Extended core live coverage relay=ws://unrelated\n"
+    )));
+    assert!(has_full_repo_live_coverage(&format!(
+        "{pending}Extended core live coverage relay=ws://source\n\
+         Processing AddFilters relay=ws://self new_full_repos=1\n"
+    )));
+    assert!(!has_full_repo_live_coverage(
+        "Extended core live coverage relay=ws://source\n\
+         Processing AddFilters relay=ws://source new_full_repos=1\n"
+    ));
+}