diff --git a/crates/openshell-server/src/compute/mutation_guard.rs b/crates/openshell-server/src/compute/mutation_guard.rs
index b6de87190b..e5ce30cbbe 100644
--- a/crates/openshell-server/src/compute/mutation_guard.rs
+++ b/crates/openshell-server/src/compute/mutation_guard.rs
@@ -1164,7 +1164,11 @@ mod tests {
         if op.is_distributed() {
             fleet.enter(op);
         }
-        tokio::time::sleep(hold).await;
+        // Windows timers round a 1 ms sleep up to ~16 ms, so yield instead.
+        let until = std::time::Instant::now() + hold;
+        while std::time::Instant::now() < until {
+            tokio::task::yield_now().await;
+        }
         if op.is_distributed() {
             fleet.leave(op);
         }
diff --git a/crates/openshell-server/src/persistence/tests.rs b/crates/openshell-server/src/persistence/tests.rs
index 93a1d94c8e..42e27690b8 100644
--- a/crates/openshell-server/src/persistence/tests.rs
+++ b/crates/openshell-server/src/persistence/tests.rs
@@ -2298,7 +2298,8 @@ async fn sqlite_concurrent_writes_return_their_own_resource_version() {
     use std::sync::Arc;
 
     const WRITERS: u64 = 8;
-    const WRITES: u64 = 25;
+    // Slow Windows fsync can starve a writer past the SQLite busy timeout.
+    const WRITES: u64 = if cfg!(windows) { 5 } else { 25 };
 
     let tmp = tempfile::tempdir().expect("tempdir");
     let url = on_disk_store_url(&tmp.path().join("openshell.db"));