diff --git a/packages/react-resizable-panels/src/Panel.ts b/packages/react-resizable-panels/src/Panel.ts
index cd107cddd..6798206f7 100644
--- a/packages/react-resizable-panels/src/Panel.ts
+++ b/packages/react-resizable-panels/src/Panel.ts
@@ -173,7 +173,7 @@ function PanelWithForwardedRef({
     id: string;
     idWasAutoGenerated: boolean;
     maxSize: number | null;
-    minSize: number | null;
+    minSize: number;
     order: number | null;
     units: PanelUnits;
   }>({