diff --git a/lib/src/cupertino_controls.dart b/lib/src/cupertino_controls.dart
index 5b6f2a772..a9be42c70 100644
--- a/lib/src/cupertino_controls.dart
+++ b/lib/src/cupertino_controls.dart
@@ -221,7 +221,7 @@ class _CupertinoControlsState extends State<CupertinoControls> with SingleTicker
   }
 
   Expanded _buildHitArea() {
-    final bool isFinished = _latestValue.position >= _latestValue.duration;
+    final bool isFinished = _latestValue.duration != null && _latestValue.position >= _latestValue.duration;
 
     return Expanded(
       child: GestureDetector(