diff --git a/lib/src/chips_input.dart b/lib/src/chips_input.dart
index 3c10a20d..d61a6e9f 100644
--- a/lib/src/chips_input.dart
+++ b/lib/src/chips_input.dart
@@ -288,7 +288,7 @@ class ChipsInputState<T> extends State<ChipsInput<T>>
     Future.delayed(const Duration(milliseconds: 300), () {
       WidgetsBinding.instance.addPostFrameCallback((_) async {
         final renderBox = context.findRenderObject() as RenderBox;
-        await Scrollable.of(context)?.position.ensureVisible(renderBox);
+        await Scrollable.of(context).position.ensureVisible(renderBox);
       });
     });
   }
@@ -387,6 +387,17 @@ class ChipsInputState<T> extends State<ChipsInput<T>>
     //TODO
   }
 
+  @override
+  void performSelector(String selectorName) {
+    //TODO
+  }
+
+  @override
+  void didChangeInputControl(
+      TextInputControl? oldControl, TextInputControl? newControl) {
+    //TODO
+  }
+
   @override
   void didUpdateWidget(covariant ChipsInput<T> oldWidget) {
     super.didUpdateWidget(oldWidget);
@@ -435,7 +446,7 @@ class ChipsInputState<T> extends State<ChipsInput<T>>
                 maxLines: 1,
                 overflow: widget.textOverflow,
                 style: widget.textStyle ??
-                    theme.textTheme.subtitle1!.copyWith(height: 1.5),
+                    theme.textTheme.titleMedium?.copyWith(height: 1.5),
               ),
             ),
             Flexible(
diff --git a/lib/src/suggestions_box_controller.dart b/lib/src/suggestions_box_controller.dart
index 127c7452..157d55eb 100644
--- a/lib/src/suggestions_box_controller.dart
+++ b/lib/src/suggestions_box_controller.dart
@@ -14,7 +14,7 @@ class SuggestionsBoxController {
   void open() {
     if (_isOpened) return;
     assert(overlayEntry != null);
-    Overlay.of(context)!.insert(overlayEntry!);
+    Overlay.of(context).insert(overlayEntry!);
     _isOpened = true;
   }