diff --git a/src/lib.rs b/src/lib.rs
index d77eaef..fc6c0fd 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -104,21 +104,30 @@ impl Spindex2d {
     /// when constructing this index. May panic if the updated points argument is longer than the
     /// original points.
     pub fn update(&self, points: &[Point2d]) {
-        {
-            let mut xs = self.xs.write().unwrap();
-            let mut ys = self.ys.write().unwrap();
-            let xpoints = self.xpoints.read().unwrap();
-            let ypoints = self.ypoints.read().unwrap();
-            for (i, point) in points.iter().enumerate() {
-                let xi = xpoints[i];
-                let yi = ypoints[i];
-                let x = PVal::new(i, point.x);
-                xs[xi] = x;
+        thread::scope(|s| {
+            s.spawn(|| {
+                let mut xs = self.xs.write().unwrap();
+                let xpoints = self.xpoints.read().unwrap();
+
+                for (i, point) in points.iter().enumerate() {
+                    let xi = xpoints[i];
+                    let x = PVal::new(i, point.x);
+                    xs[xi] = x;
+                }
+            });
+
+            s.spawn(|| {
+                let mut ys = self.ys.write().unwrap();
+                let ypoints = self.ypoints.read().unwrap();
+
+                for (i, point) in points.iter().enumerate() {
+                    let yi = ypoints[i];
+                    let y = PVal::new(i, point.y);
+                    ys[yi] = y;
+                }
+            });
+        });
 
-                let y = PVal::new(i, point.y);
-                ys[yi] = y;
-            }
-        }
         self.sort();
     }