diff --git a/lib/src/rotate.dart b/lib/src/rotate.dart
index 7a8d5fe..2f74b53 100644
--- a/lib/src/rotate.dart
+++ b/lib/src/rotate.dart
@@ -142,6 +142,7 @@ class _RotatingTextState extends State<RotateAnimatedTextKit>
 
   @override
   void dispose() {
+    _timer?.cancel();
     _controller?.stop();
     _controller?.dispose();
     super.dispose();
@@ -268,6 +269,7 @@ class _RotatingTextState extends State<RotateAnimatedTextKit>
 
   void _animationEndCallback(state) {
     if (state == AnimationStatus.completed) {
+      assert(null == _timer || !_timer.isActive);
       _timer = Timer(_texts[_index]['pause'], _nextAnimation);
     }
   }
@@ -282,6 +284,7 @@ class _RotatingTextState extends State<RotateAnimatedTextKit>
 
         _setPause();
 
+        assert(null == _timer || !_timer.isActive);
         _timer = Timer(_texts[_index]['pause'], _nextAnimation);
       }
     }
diff --git a/lib/src/scale.dart b/lib/src/scale.dart
index 288bb20..19eb83a 100644
--- a/lib/src/scale.dart
+++ b/lib/src/scale.dart
@@ -147,6 +147,7 @@ class _ScaleTextState extends State<ScaleAnimatedTextKit>
 
   @override
   void dispose() {
+    _timer?.cancel();
     _controller?.stop();
     _controller?.dispose();
     super.dispose();
@@ -255,6 +256,7 @@ class _ScaleTextState extends State<ScaleAnimatedTextKit>
   void _animationEndCallback(state) {
     if (state == AnimationStatus.completed) {
       _isCurrentlyPausing = true;
+      assert(null == _timer || !_timer.isActive);
       _timer = Timer(_texts[_index]['pause'], _nextAnimation);
     }
   }
@@ -274,6 +276,7 @@ class _ScaleTextState extends State<ScaleAnimatedTextKit>
 
         _setPause();
 
+        assert(null == _timer || !_timer.isActive);
         _timer =
             Timer(Duration(milliseconds: max(pause, left)), _nextAnimation);
       }
diff --git a/lib/src/typer.dart b/lib/src/typer.dart
index 979709c..c4469fb 100644
--- a/lib/src/typer.dart
+++ b/lib/src/typer.dart
@@ -125,6 +125,7 @@ class _TyperState extends State<TyperAnimatedTextKit>
 
   @override
   void dispose() {
+    _timer?.cancel();
     _controller?.stop();
     _controller?.dispose();
     super.dispose();
@@ -207,6 +208,7 @@ class _TyperState extends State<TyperAnimatedTextKit>
   void _animationEndCallback(state) {
     if (state == AnimationStatus.completed) {
       _setPause();
+      assert(null == _timer || !_timer.isActive);
       _timer = Timer(_texts[_index]['pause'], _nextAnimation);
     }
   }
@@ -227,6 +229,7 @@ class _TyperState extends State<TyperAnimatedTextKit>
 
         _setPause();
 
+        assert(null == _timer || !_timer.isActive);
         _timer =
             Timer(Duration(milliseconds: max(pause, left)), _nextAnimation);
       }