diff --git a/codex-rs/app-server/tests/suite/v2/experimental_feature_list.rs b/codex-rs/app-server/tests/suite/v2/experimental_feature_list.rs
index 3063830d5a..07bdd0bde1 100644
--- a/codex-rs/app-server/tests/suite/v2/experimental_feature_list.rs
+++ b/codex-rs/app-server/tests/suite/v2/experimental_feature_list.rs
@@ -24,7 +24,7 @@ use std::collections::BTreeMap;
 use tempfile::TempDir;
 use tokio::time::timeout;
 
-const DEFAULT_TIMEOUT: Duration = Duration::from_secs(10);
+const DEFAULT_TIMEOUT: Duration = Duration::from_secs(30);
 
 #[tokio::test]
 async fn experimental_feature_list_returns_feature_metadata_with_stage() -> Result<()> {
diff --git a/codex-rs/connectors/src/lib.rs b/codex-rs/connectors/src/lib.rs
index d7c5fb405c..dea4e57dff 100644
--- a/codex-rs/connectors/src/lib.rs
+++ b/codex-rs/connectors/src/lib.rs
@@ -419,6 +419,9 @@ mod tests {
     use std::sync::atomic::AtomicUsize;
     use std::sync::atomic::Ordering;
 
+    static ALL_CONNECTORS_CACHE_TEST_LOCK: LazyLock<tokio::sync::Mutex<()>> =
+        LazyLock::new(|| tokio::sync::Mutex::new(()));
+
     fn cache_key(id: &str) -> AllConnectorsCacheKey {
         AllConnectorsCacheKey::new(
             "https://chatgpt.example".to_string(),
@@ -445,6 +448,8 @@ mod tests {
 
     #[tokio::test]
     async fn list_all_connectors_uses_shared_cache() -> anyhow::Result<()> {
+        let _cache_guard = ALL_CONNECTORS_CACHE_TEST_LOCK.lock().await;
+
         let calls = Arc::new(AtomicUsize::new(0));
         let call_counter = Arc::clone(&calls);
         let key = cache_key("shared");
@@ -483,6 +488,8 @@ mod tests {
 
     #[tokio::test]
     async fn list_all_connectors_merges_and_normalizes_directory_apps() -> anyhow::Result<()> {
+        let _cache_guard = ALL_CONNECTORS_CACHE_TEST_LOCK.lock().await;
+
         let key = cache_key("merged");
         let calls = Arc::new(AtomicUsize::new(0));
         let call_counter = Arc::clone(&calls);
diff --git a/codex-rs/core/tests/suite/compact_remote.rs b/codex-rs/core/tests/suite/compact_remote.rs
index 4b1eaa44d2..e694e198d3 100644
--- a/codex-rs/core/tests/suite/compact_remote.rs
+++ b/codex-rs/core/tests/suite/compact_remote.rs
@@ -791,7 +791,7 @@ async fn remote_compact_trim_estimate_uses_session_base_instructions() -> Result
     let override_retained_call_id = "override-retained-call";
     let override_trailing_call_id = "override-trailing-call";
     let retained_command = "printf retained-shell-output";
-    let trailing_command = "printf trailing-shell-output";
+    let trailing_command = "printf '%020000d' 0";
 
     let baseline_harness = TestCodexHarness::with_builder(
         test_codex()
@@ -880,9 +880,12 @@ async fn remote_compact_trim_estimate_uses_session_base_instructions() -> Result
     let baseline_input_tokens = estimate_compact_input_tokens(&baseline_compact_request);
     let baseline_payload_tokens = estimate_compact_payload_tokens(&baseline_compact_request);
 
-    let override_base_instructions =
-        format!("REMOTE_BASE_INSTRUCTIONS_OVERRIDE {}", "x".repeat(120_000));
-    let override_context_window = baseline_payload_tokens.saturating_add(1_000);
+    let override_base_instructions = format!(
+        "{}\nREMOTE_BASE_INSTRUCTIONS_OVERRIDE {}",
+        baseline_compact_request.instructions_text(),
+        "x".repeat(4_000)
+    );
+    let override_context_window = baseline_payload_tokens.saturating_add(500);
     let pretrim_override_estimate =
         baseline_input_tokens.saturating_add(approx_token_count(&override_base_instructions));
     assert!(