From 361ea289526d3737fabd857dd7c6c895f9f89532 Mon Sep 17 00:00:00 2001
From: Abraham Egnor <abraham.egnor@mongodb.com>
Date: Fri, 14 Nov 2025 11:52:35 +0000
Subject: [PATCH 1/2] focused fix

---
 driver/src/client.rs | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/driver/src/client.rs b/driver/src/client.rs
index c0ef225d6..41f97c762 100644
--- a/driver/src/client.rs
+++ b/driver/src/client.rs
@@ -550,10 +550,12 @@ impl Client {
 
                         watcher.request_immediate_check();
 
-                        let change_occurred = start_time.elapsed() < timeout
-                            && watcher
-                                .wait_for_update(timeout - start_time.elapsed())
-                                .await;
+                        let elapsed = start_time.elapsed();
+                        let change_occurred = elapsed < timeout
+                            && match timeout.checked_sub(elapsed) {
+                                Some(remaining) => watcher.wait_for_update(remaining).await,
+                                None => false,
+                            };
                         if !change_occurred {
                             let error: Error = ErrorKind::ServerSelection {
                                 message: state

From e2d1670847eb46ca25d99ef3860d336d0103e8b9 Mon Sep 17 00:00:00 2001
From: Abraham Egnor <abraham.egnor@mongodb.com>
Date: Fri, 14 Nov 2025 12:13:26 +0000
Subject: [PATCH 2/2] revised fix

---
 driver/src/client.rs | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/driver/src/client.rs b/driver/src/client.rs
index 41f97c762..3f43725f0 100644
--- a/driver/src/client.rs
+++ b/driver/src/client.rs
@@ -552,10 +552,11 @@ impl Client {
 
                         let elapsed = start_time.elapsed();
                         let change_occurred = elapsed < timeout
-                            && match timeout.checked_sub(elapsed) {
-                                Some(remaining) => watcher.wait_for_update(remaining).await,
-                                None => false,
-                            };
+                            && watcher
+                                .wait_for_update(
+                                    timeout.checked_sub(elapsed).unwrap_or(Duration::ZERO),
+                                )
+                                .await;
                         if !change_occurred {
                             let error: Error = ErrorKind::ServerSelection {
                                 message: state
@@ -615,10 +616,10 @@ impl Client {
             if let Some(desc) = topology.description.primary() {
                 return Some(desc.clone());
             }
-            if !watcher
-                .wait_for_update(timeout - start_time.elapsed())
-                .await
-            {
+            let remaining = timeout
+                .checked_sub(start_time.elapsed())
+                .unwrap_or(Duration::ZERO);
+            if !watcher.wait_for_update(remaining).await {
                 return None;
             }
         }