diff --git a/src/allotment.tsx b/src/allotment.tsx
index 5507cc5f..d3483ca3 100644
--- a/src/allotment.tsx
+++ b/src/allotment.tsx
@@ -118,10 +118,10 @@ const Allotment = forwardRef<AllotmentHandle, AllotmentProps>(
       const options: SplitViewOptions = {
         orientation: vertical ? Orientation.Vertical : Orientation.Horizontal,
         ...(initializeSizes &&
-          sizes && {
+          defaultSizes && {
             descriptor: {
-              size: sizes.reduce((a, b) => a + b, 0),
-              views: sizes.map((size, index) => ({
+              size: defaultSizes.reduce((a, b) => a + b, 0),
+              views: defaultSizes.map((size, index) => ({
                 container: [...splitViewViewRef.current.values()][index],
                 size: size,
                 view: {
diff --git a/stories/allotment.stories.tsx b/stories/allotment.stories.tsx
index 0ce3ac99..efeb440c 100644
--- a/stories/allotment.stories.tsx
+++ b/stories/allotment.stories.tsx
@@ -208,3 +208,15 @@ export const Reset: Story<AllotmentProps> = (args) => {
   );
 };
 Reset.args = {};
+
+export const DefaultSize: Story = () => {
+  return (
+    <div className={styles.container}>
+      <Allotment defaultSizes={[200, 400]}>
+        <div className={styles.content}>div1</div>
+        <div className={styles.content}>div2</div>
+      </Allotment>
+    </div>
+  );
+};
+DefaultSize.args = {};