diff --git a/CHANGELOG.md b/CHANGELOG.md
index 47bd5f0..bd15449 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -20,6 +20,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+- Keep purgatory announcements, state events, and PR events alive while a
+  concrete background Git sync for their repository is actively running. A
+  large healthy clone can exceed the nominal 30-minute purgatory window;
+  queued and backoff-only work remains eligible for normal expiry so broken
+  repositories cannot extend retention indefinitely.
 - Preserve purgatory and rejected-event recovery across abrupt termination.
   Their snapshots now remain after restore and are atomically replaced every
   60 seconds, bounding crash loss to one interval instead of consuming the
diff --git a/docs/explanation/architecture.md b/docs/explanation/architecture.md
index b4f1444..3737c64 100644
--- a/docs/explanation/architecture.md
+++ b/docs/explanation/architecture.md
@@ -307,6 +307,8 @@ pub struct Purgatory {
 5. **Automatic Expiry**: 30-minute default expiry, extensible during processing
    - Background cleanup task runs every 60 seconds
    - Removes expired entries from all stores
+   - Defers matching expiry while a concrete background Git sync is actively
+     running; queued/backoff work receives no extension
 
 #### Data Types
 
diff --git a/docs/explanation/purgatory-design.md b/docs/explanation/purgatory-design.md
index bc98052..a801e85 100644
--- a/docs/explanation/purgatory-design.md
+++ b/docs/explanation/purgatory-design.md
@@ -348,6 +348,8 @@ fetch_repository_data_with_purgatory() checks DB + purgatory
 The protocol specifies 30-minute expiry for announcements. We implement a two-phase soft expiry:
 
 **Phase 1 — Initial 30-minute expiry (`soft_expired == false`):**
+- Defer the expiry sweep while a concrete background Git sync for the
+  repository is actively running
 - Delete the bare git repo (frees disk space, respects protocol expiry)
 - Set `soft_expired = true`
 - Extend `expires_at` by 24 hours (`SOFT_EXPIRY_EXTENDED`)
@@ -378,6 +380,14 @@ The 30-minute purgatory timer is reset (extended) in three scenarios:
 
 All three call `purgatory.extend_announcement_expiry(owner, identifier, 1800s)`.
 
+Background Git synchronization does not reset the 30-minute deadline. Instead,
+the expiry sweep skips matching announcements, state events and PR events only
+while `sync_identifier` is actively running. This lets a large but healthy
+clone finish without allowing an unavailable repository to live forever:
+queue entries waiting for their next attempt or in backoff remain eligible for
+normal expiry. When active work finishes, it either promotes the satisfied
+events or the next sweep expires any still-unsatisfied entries.
+
 ### Purgatory Lifecycle
 
 ```
diff --git a/src/purgatory/mod.rs b/src/purgatory/mod.rs
index d2d9932..48baa5a 100644
--- a/src/purgatory/mod.rs
+++ b/src/purgatory/mod.rs
@@ -344,6 +344,35 @@ impl Purgatory {
         false
     }
 
+    /// Whether a concrete background Git sync is currently running for an
+    /// identifier.
+    ///
+    /// Queue membership alone is deliberately insufficient: entries waiting
+    /// for their next backoff attempt must still expire normally when remote
+    /// Git data remains unavailable. Only the interval in which
+    /// `sync_identifier` is actively working protects matching purgatory
+    /// entries from the expiry sweep.
+    fn identifier_sync_in_progress(&self, identifier: &str) -> bool {
+        self.sync_queue
+            .get(identifier)
+            .is_some_and(|entry| entry.in_progress)
+    }
+
+    /// Whether any repository referenced by an event has active Git sync.
+    fn event_sync_in_progress(&self, event: &Event) -> bool {
+        event.tags.iter().any(|tag| {
+            let values = tag.clone().to_vec();
+            if values.len() < 2 || values[0] != "a" || !values[1].starts_with("30617:") {
+                return false;
+            }
+
+            values[1]
+                .splitn(3, ':')
+                .nth(2)
+                .is_some_and(|identifier| self.identifier_sync_in_progress(identifier))
+        })
+    }
+
     /// Get a reference to the sync queue (for the sync loop).
     pub fn sync_queue(&self) -> &Arc<DashMap<String, SyncQueueEntry>> {
         &self.sync_queue
@@ -1143,7 +1172,9 @@ impl Purgatory {
         let expired_announcements: Vec<(PublicKey, String, PathBuf, EventId, bool)> = self
             .announcement_purgatory
             .iter()
-            .filter(|entry| entry.value().expires_at <= now)
+            .filter(|entry| {
+                entry.value().expires_at <= now && !self.identifier_sync_in_progress(&entry.key().1)
+            })
             .map(|entry| {
                 let key = entry.key();
                 let v = entry.value();
@@ -1224,6 +1255,10 @@ impl Purgatory {
 
         // Remove expired state events and mark them as expired
         self.state_events.retain(|identifier, entries| {
+            if self.identifier_sync_in_progress(identifier) {
+                return true;
+            }
+
             let original_len = entries.len();
 
             // Log and collect expired entries before removing
@@ -1267,7 +1302,14 @@ impl Purgatory {
         let expired_prs: Vec<_> = self
             .pr_events
             .iter()
-            .filter(|entry| entry.value().expires_at <= now)
+            .filter(|entry| {
+                let value = entry.value();
+                value.expires_at <= now
+                    && !value
+                        .event
+                        .as_ref()
+                        .is_some_and(|event| self.event_sync_in_progress(event))
+            })
             .map(|entry| {
                 let pr_entry = entry.value();
                 let event_id_str = entry.key().clone();
@@ -2146,6 +2188,80 @@ fn test_cleanup_preserves_non_expired_entries() {
     assert_eq!(pr_count, 1);
 }
 
+#[test]
+fn cleanup_defers_expiry_only_while_repository_sync_is_active() {
+    let purgatory = Purgatory::new(PathBuf::new());
+    let keys = Keys::generate();
+    let identifier = "large-repository";
+
+    let announcement = EventBuilder::new(Kind::GitRepoAnnouncement, "")
+        .finalize(&keys)
+        .unwrap();
+    purgatory.add_announcement(
+        announcement,
+        identifier.to_string(),
+        keys.public_key(),
+        PathBuf::from("/path/that/does/not/exist"),
+        HashSet::new(),
+    );
+
+    let state = EventBuilder::new(Kind::RepoState, "")
+        .finalize(&keys)
+        .unwrap();
+    purgatory.add_state(state, identifier.to_string(), keys.public_key(), true);
+
+    let pr = EventBuilder::new(Kind::GitPatch, "")
+        .tag(Tag::custom(
+            "a",
+            vec![format!("30617:{}:{identifier}", keys.public_key().to_hex())],
+        ))
+        .finalize(&keys)
+        .unwrap();
+    purgatory.add_pr(pr, "pr-event".to_string(), "commit".to_string(), true);
+
+    let expired_at = Instant::now() - Duration::from_secs(1);
+    purgatory
+        .announcement_purgatory
+        .get_mut(&(keys.public_key(), identifier.to_string()))
+        .unwrap()
+        .expires_at = expired_at;
+    purgatory.state_events.get_mut(identifier).unwrap()[0].expires_at = expired_at;
+    purgatory.pr_events.get_mut("pr-event").unwrap().expires_at = expired_at;
+    purgatory
+        .sync_queue
+        .get_mut(identifier)
+        .unwrap()
+        .in_progress = true;
+
+    let removed = purgatory.cleanup();
+    assert_eq!(removed, (0, 0, 0));
+    assert!(
+        !purgatory
+            .find_announcement(&keys.public_key(), identifier)
+            .unwrap()
+            .soft_expired
+    );
+    assert_eq!(purgatory.count(), (1, 1, 1));
+    assert_eq!(purgatory.expired_count(), 0);
+
+    // An entry merely waiting in the queue or in backoff is not active work.
+    // Once the concrete Git operation ends, an unsatisfied event may expire.
+    purgatory
+        .sync_queue
+        .get_mut(identifier)
+        .unwrap()
+        .in_progress = false;
+    let removed = purgatory.cleanup();
+    assert_eq!(removed, (0, 1, 1));
+    assert!(
+        purgatory
+            .find_announcement(&keys.public_key(), identifier)
+            .unwrap()
+            .soft_expired
+    );
+    assert_eq!(purgatory.expired_count(), 2);
+}
+
 #[test]
 fn test_cleanup_mixed_expired_and_fresh() {
     use std::time::Duration;