diff --git a/apps/vectorcraft/src/control_server.rs b/apps/vectorcraft/src/control_server.rs
index 21eacd61a..529100513 100644
--- a/apps/vectorcraft/src/control_server.rs
+++ b/apps/vectorcraft/src/control_server.rs
@@ -383,7 +383,10 @@ mod tests {
         });
         let mut reader = BufReader::new(client.try_clone().unwrap());
         for id in [1, 2] {
-            writeln!(client, "{}", json!({"id": id, "method": "inspect"})).unwrap();
+            // The client sends each line in one write. `writeln!` on the socket sends the JSON in many
+            // small writes, and when the machine is busy, a pause of more than the 120 ms line deadline
+            // between two of them closes the connection.
+            client.write_all(format!("{}\n", json!({"id": id, "method": "inspect"})).as_bytes()).unwrap();
             let mut line = String::new();
             reader.read_line(&mut line).unwrap();
             assert_eq!(serde_json::from_str::<Value>(&line).unwrap(), json!({"id": id, "ok": true}));
diff --git a/crates/ui-egui/src/canvas.rs b/crates/ui-egui/src/canvas.rs
index fe1f71e68..202bfc10f 100644
--- a/crates/ui-egui/src/canvas.rs
+++ b/crates/ui-egui/src/canvas.rs
@@ -4411,7 +4411,7 @@ mod tests {
         app.session.pointer(&PointerEvent::new(PointerKind::Up, 181.9, 131.3), view).unwrap();
         assert!(upload(&mut app).is_none(), "not rendered on this thread");
         assert!(app.canvas.worker.as_ref().and_then(|w| w.pending.as_ref()).is_some_and(|k| !k.interacting), "sent to the worker");
-        let until = std::time::Instant::now() + std::time::Duration::from_secs(10);
+        let until = std::time::Instant::now() + std::time::Duration::from_secs(60);
         let mut after = None;
         while after.is_none() && std::time::Instant::now() < until {
             std::thread::sleep(std::time::Duration::from_millis(5));
diff --git a/crates/ui-egui/src/tests_sysclip_probe.rs b/crates/ui-egui/src/tests_sysclip_probe.rs
index e09ba3a09..48e4f2e34 100644
--- a/crates/ui-egui/src/tests_sysclip_probe.rs
+++ b/crates/ui-egui/src/tests_sysclip_probe.rs
@@ -117,7 +117,7 @@ fn a_slow_clipboard_is_read_off_the_ui_thread() {
     frame(&mut app);
     assert!(t0.elapsed() < Duration::from_millis(300), "the frame waited on the clipboard: {:?}", t0.elapsed());
     // The probe's verdict (the UI's own handle would say no) enables Paste once it arrives.
-    assert!(frames_until(&mut app, Duration::from_secs(3), |app| app.system_paste), "the probe's verdict never arrived");
+    assert!(frames_until(&mut app, Duration::from_secs(60), |app| app.system_paste), "the probe's verdict never arrived");
     assert!(menus::enabled(&app, "edit.paste"));
     let threads = rec.threads.lock().unwrap().clone();
     assert!(threads.iter().all(|n| n.as_deref() == Some("vectorcraft-clip")), "checked on: {threads:?}");
@@ -128,7 +128,7 @@ fn the_probe_rests_after_a_copy_and_stops_with_the_app() {
     let rec = Arc::new(Recorder::default());
     let mut app = app(&rec, Duration::ZERO, false, Some(true));
     run(&mut app, "file.new", json!({"width": 100, "height": 100}));
-    assert!(frames_until(&mut app, Duration::from_secs(2), |app| app.system_paste));
+    assert!(frames_until(&mut app, Duration::from_secs(60), |app| app.system_paste));
     // Something copied in the app enables Paste alone: the clipboard isn't read any more.
     copy_rect(&mut app);
     frames_until(&mut app, Duration::from_millis(50), |_| false);
@@ -149,7 +149,7 @@ fn without_its_thread_the_check_runs_in_line_again() {
     // The probe's clipboard panics: its thread ends.
     let mut app = app(&rec, Duration::ZERO, true, None);
     run(&mut app, "file.new", json!({"width": 100, "height": 100}));
-    assert!(frames_until(&mut app, Duration::from_secs(2), |app| app.system_paste), "no fallback");
+    assert!(frames_until(&mut app, Duration::from_secs(60), |app| app.system_paste), "no fallback");
     assert!(app.clipboard_probe.is_none());
     let threads = rec.threads.lock().unwrap().clone();
     assert_eq!(threads.first().cloned().flatten().as_deref(), Some("vectorcraft-clip"), "{threads:?}");