diff --git a/CHANGELOG.md b/CHANGELOG.md
index edbf8a97..afd8b0c6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,6 @@
 Thanks to all contributers who improved notistack by opening an issue/PR.
 
-### `notistack@0.9.15`
+### `notistack@0.9.16`
 ###### to be published
 * **@pctestjfarz**: Add swipe to dismiss feature [#138](https://github.com/iamhosseindhv/notistack/issues/138) 
 * **@molynerd**: Add support to update content of snackbar in place [#50](https://github.com/iamhosseindhv/notistack/issues/50)
@@ -8,6 +8,14 @@ Thanks to all contributers who improved notistack by opening an issue/PR.
 
 
 
+<br />
+
+
+### `notistack@0.9.15`
+###### May 17, 2020
+* **@nebojsanb**: Fix bug with displaying snackbars [#270](https://github.com/iamhosseindhv/notistack/issues/270) 
+
+
 <br />
 
 
diff --git a/src/SnackbarProvider.tsx b/src/SnackbarProvider.tsx
index e44f68c4..fc9afaf8 100644
--- a/src/SnackbarProvider.tsx
+++ b/src/SnackbarProvider.tsx
@@ -171,6 +171,10 @@ class SnackbarProvider extends Component<SnackbarProviderProps, State> {
      * Set the entered state of the snackbar with the given key.
      */
     handleEnteredSnack: TransitionHandlerProps['onEntered'] = (node, isAppearing, key) => {
+        if (!key) {
+            throw new Error('handleEnteredSnack Cannot be called with undefined key');
+        }
+
         this.setState(({ snacks }) => ({
             snacks: snacks.map(item => (
                 item.key === key ? { ...item, entered: true } : { ...item }
@@ -223,7 +227,13 @@ class SnackbarProvider extends Component<SnackbarProviderProps, State> {
      * waiting in the queue (if any). If after this process the queue is not empty, the
      * oldest message is dismissed.
      */
-    handleExitedSnack: TransitionHandlerProps['onExited'] = (event, key) => {
+    // @ts-ignore
+    handleExitedSnack: TransitionHandlerProps['onExited'] = (event, key1, key2) => {
+        const key = key1 || key2;
+        if (!key) {
+            throw new Error('handleExitedSnack Cannot be called with undefined key');
+        }
+
         this.setState((state) => {
             const newState = this.processQueue({
                 ...state,