diff --git a/src/engine.ts b/src/engine.ts
index 0f45d48..a3f8d42 100644
--- a/src/engine.ts
+++ b/src/engine.ts
@@ -186,7 +186,7 @@ export class RunningEngine {
 
         this.engine.runRenderLoop(() => {
             this.performanceMonitor.sampleFrame();
-            this.scene.gravity = this.gravity.scale(this.performanceMonitor.averageFrameTime / 1000.0);
+            this.scene.gravity = this.gravity.scale(this.frameRateScale);
             try {
                 Array.from(navigator.getGamepads()).forEach(gp => {
                     if (gp !== null) this.checkGamepadInput(gp);
@@ -209,6 +209,10 @@ export class RunningEngine {
         c.ellipsoid = new Vector3(0.25, this.options.initialPos.y / 2, 0.25);
     }
 
+    get frameRateScale(): number {
+        return this.performanceMonitor.averageFrameTime / 1000.0;
+    }
+
     get inXR(): boolean {
         return (this.xr !== null) && (this.xr.baseExperience.state === WebXRState.IN_XR);
     }
@@ -295,7 +299,7 @@ export class RunningEngine {
 
     jump() {
         if (Math.abs(this.camera.cameraDirection.y) < 0.1) {
-            this.camera.cameraDirection.y += 1;
+            this.camera.cameraDirection.y += 1 * this.frameRateScale;
         }
     }
 
diff --git a/src/index.ts b/src/index.ts
index 1725b99..6efe3fa 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -22,6 +22,18 @@ assertion type SceneHandle(ds: Embedded<Ref>);
 
 function interpretScene(myId: string, runningEngine: RunningEngine, rootMesh: Mesh, sceneDs: Ref) {
     at sceneDs {
+        during SceneProtocol.Gravity($direction: Shapes.LiteralVector3) => {
+            Turn.active.sync(sceneDs).then(() => {
+                console.log('enabling gravity');
+                runningEngine.applyGravity = true;
+            });
+            on stop {
+                console.log('disabling gravity');
+                runningEngine.applyGravity = false;
+            }
+            runningEngine.gravity = new Vector3(direction.x, direction.y, direction.z);
+        }
+
         during Shapes.Sprite({ "name": $name: string, "formals": $formals }) => spawn named `sprite:${name}` {
             if (name === myId) {
                 console.log('ignoring sprite', name);
@@ -52,12 +64,6 @@ function spriteMain(env: Environment, runningEngine: RunningEngine, rootMesh: Me
             currentShape = currentShape.reconcile(env, env.spriteName, shape);
             currentShape.rootnode.parent = rootMesh;
         }
-
-        during SceneProtocol.Gravity($direction: Shapes.LiteralVector3) => {
-            runningEngine.applyGravity = true;
-            on stop runningEngine.applyGravity = false;
-            runningEngine.gravity = new Vector3(direction.x, direction.y, direction.z);
-        }
     }
 }