diff --git a/src/stories/lottie-control-segments.js b/src/stories/lottie-control-segments.js
index 5b430a7..37aef96 100644
--- a/src/stories/lottie-control-segments.js
+++ b/src/stories/lottie-control-segments.js
@@ -44,7 +44,7 @@ export default class LottieControlSegment extends React.Component {
       <input
         style={centerStyle}
         type="range" value={speed} min="0" max="3" step="0.5"
-        onChange={e => this.setState({ speed: e.currentTarget.value })}
+        onChange={e => this.setState({ speed: +e.currentTarget.value })}
       />
       <p style={centerStyle}>Segment range: [{startFrame}, {endFrame}]</p>
       <div style={centerStyle}>
diff --git a/src/stories/lottie-control.js b/src/stories/lottie-control.js
index 28f8f48..e6ae232 100644
--- a/src/stories/lottie-control.js
+++ b/src/stories/lottie-control.js
@@ -41,7 +41,7 @@ export default class LottieControl extends React.Component {
       <input
         style={centerStyle}
         type="range" value={speed} min="0" max="3" step="0.5"
-        onChange={e => this.setState({ speed: e.currentTarget.value })}
+        onChange={e => this.setState({ speed: +e.currentTarget.value })}
       />
       <button
         style={centerStyle}