diff --git a/codex-rs/core/src/rollout/tests.rs b/codex-rs/core/src/rollout/tests.rs
index ccd476b8c..a4bd72433 100644
--- a/codex-rs/core/src/rollout/tests.rs
+++ b/codex-rs/core/src/rollout/tests.rs
@@ -62,6 +62,10 @@ async fn insert_state_db_thread(
         codex_state::StateRuntime::init(home.to_path_buf(), TEST_PROVIDER.to_string(), None)
             .await
             .expect("state db should initialize");
+    runtime
+        .mark_backfill_complete(None)
+        .await
+        .expect("backfill should be complete");
     let created_at = chrono::Utc
         .with_ymd_and_hms(2025, 1, 3, 12, 0, 0)
         .single()
@@ -280,6 +284,10 @@ async fn find_thread_path_repairs_missing_db_row_after_filesystem_fallback() {
         codex_state::StateRuntime::init(home.to_path_buf(), TEST_PROVIDER.to_string(), None)
             .await
             .expect("state db should initialize");
+    _runtime
+        .mark_backfill_complete(None)
+        .await
+        .expect("backfill should be complete");
 
     let found = crate::rollout::find_thread_path_by_id_str(home, &uuid.to_string())
         .await
diff --git a/codex-rs/core/src/state_db.rs b/codex-rs/core/src/state_db.rs
index 97846cdcf..ed2e8c264 100644
--- a/codex-rs/core/src/state_db.rs
+++ b/codex-rs/core/src/state_db.rs
@@ -54,30 +54,20 @@ pub(crate) async fn init_if_enabled(
             return None;
         }
     };
-    let should_backfill = match runtime.get_backfill_state().await {
-        Ok(state) => state.status != codex_state::BackfillStatus::Complete,
+    let backfill_state = match runtime.get_backfill_state().await {
+        Ok(state) => state,
         Err(err) => {
             warn!(
                 "failed to read backfill state at {}: {err}",
                 config.codex_home.display()
             );
-            true
+            return None;
         }
     };
-    if should_backfill {
-        let runtime_for_backfill = Arc::clone(&runtime);
-        let config_for_backfill = config.clone();
-        let otel_for_backfill = otel.cloned();
-        tokio::task::spawn(async move {
-            metadata::backfill_sessions(
-                runtime_for_backfill.as_ref(),
-                &config_for_backfill,
-                otel_for_backfill.as_ref(),
-            )
-            .await;
-        });
+    if backfill_state.status != codex_state::BackfillStatus::Complete {
+        metadata::backfill_sessions(runtime.as_ref(), config, otel).await;
     }
-    Some(runtime)
+    require_backfill_complete(runtime, config.codex_home.as_path()).await
 }
 
 /// Get the DB if the feature is enabled and the DB exists.
@@ -88,13 +78,14 @@ pub async fn get_state_db(config: &Config, otel: Option<&OtelManager>) -> Option
     {
         return None;
     }
-    codex_state::StateRuntime::init(
+    let runtime = codex_state::StateRuntime::init(
         config.codex_home.clone(),
         config.model_provider_id.clone(),
         otel.cloned(),
     )
     .await
-    .ok()
+    .ok()?;
+    require_backfill_complete(runtime, config.codex_home.as_path()).await
 }
 
 /// Open the state runtime when the SQLite file exists, without feature gating.
@@ -112,7 +103,31 @@ pub async fn open_if_present(codex_home: &Path, default_provider: &str) -> Optio
     )
     .await
     .ok()?;
-    Some(runtime)
+    require_backfill_complete(runtime, codex_home).await
+}
+
+async fn require_backfill_complete(
+    runtime: StateDbHandle,
+    codex_home: &Path,
+) -> Option<StateDbHandle> {
+    match runtime.get_backfill_state().await {
+        Ok(state) if state.status == codex_state::BackfillStatus::Complete => Some(runtime),
+        Ok(state) => {
+            warn!(
+                "state db backfill not complete at {} (status: {})",
+                codex_home.display(),
+                state.status.as_str()
+            );
+            None
+        }
+        Err(err) => {
+            warn!(
+                "failed to read backfill state at {}: {err}",
+                codex_home.display()
+            );
+            None
+        }
+    }
 }
 
 fn cursor_to_anchor(cursor: Option<&Cursor>) -> Option<codex_state::Anchor> {
diff --git a/codex-rs/core/tests/suite/rollout_list_find.rs b/codex-rs/core/tests/suite/rollout_list_find.rs
index 5b545384b..236a70279 100644
--- a/codex-rs/core/tests/suite/rollout_list_find.rs
+++ b/codex-rs/core/tests/suite/rollout_list_find.rs
@@ -59,6 +59,7 @@ async fn upsert_thread_metadata(codex_home: &Path, thread_id: ThreadId, rollout_
     let runtime = StateRuntime::init(codex_home.to_path_buf(), "test-provider".to_string(), None)
         .await
         .unwrap();
+    runtime.mark_backfill_complete(None).await.unwrap();
     let mut builder = ThreadMetadataBuilder::new(
         thread_id,
         rollout_path,