diff --git a/packages/physics/matter/world.js b/packages/physics/matter/world.js
index 7a98db5..8ca1779 100644
--- a/packages/physics/matter/world.js
+++ b/packages/physics/matter/world.js
@@ -53,8 +53,8 @@ export class World extends AbstractWorld {
     // Update simulation.
     elapsed += this.elapsedRemainder;
     const stepTime = this.stepTime;
+    const stepTimeInMs = stepTime * 1000;
     while (elapsed >= stepTime) {
-      const stepTimeInMs = stepTime * 1000;
       Engine.update(this.engine, stepTimeInMs);
       elapsed -= stepTime;
     }