diff --git a/src/ui/components/Interactive.js b/src/ui/components/Interactive.js
index 687f69b6b..bf4de175a 100644
--- a/src/ui/components/Interactive.js
+++ b/src/ui/components/Interactive.js
@@ -6,7 +6,7 @@
  */
 
 import type {Rect} from '../../utils/geometry.tsx';
-import LowPassFilter from '../../utils/LowPassFilter.js';
+import LowPassFilter from '../../utils/LowPassFilter.tsx';
 import {
   getDistanceTo,
   maybeSnapLeft,
diff --git a/src/utils/LowPassFilter.js b/src/utils/LowPassFilter.tsx
similarity index 96%
rename from src/utils/LowPassFilter.js
rename to src/utils/LowPassFilter.tsx
index eb437729f..8db8e4a7f 100644
--- a/src/utils/LowPassFilter.js
+++ b/src/utils/LowPassFilter.tsx
@@ -6,7 +6,7 @@
  */
 
 export default class LowPassFilter {
-  constructor(smoothing?: number = 0.9) {
+  constructor(smoothing: number = 0.9) {
     this.smoothing = smoothing;
     this.buffer = [];
     this.bufferMaxSize = 5;