diff --git a/.changeset/pink-impalas-scream.md b/.changeset/pink-impalas-scream.md
new file mode 100644
index 00000000..0ca861df
--- /dev/null
+++ b/.changeset/pink-impalas-scream.md
@@ -0,0 +1,6 @@
+---
+'thebe-react': patch
+'thebe-core': patch
+---
+
+Fixes a cross package import from `core` to `react` that caused downstream SSR to fail
diff --git a/packages/core/src/types.ts b/packages/core/src/types.ts
index 88010854..5b5de244 100644
--- a/packages/core/src/types.ts
+++ b/packages/core/src/types.ts
@@ -5,7 +5,6 @@ import type { IRenderMimeRegistry } from '@jupyterlab/rendermime';
 import type ThebeServer from './server';
 import type { ServerStatusEvent } from './events';
 import type { Config } from './config';
-import type ThebeNotebook from './notebook';
 export type CellKind = 'code' | 'markdown';
 export type JsonObject = Record<string, any>;
 export type SessionIModel = Session.IModel;
@@ -98,7 +97,7 @@ export interface IThebeCell extends IPassiveCell {
   source: string;
   session?: ThebeSession;
   metadata: JsonObject;
-  notebook?: ThebeNotebook;
+  notebookId?: string;
   readonly isBusy: boolean;
   readonly isAttached: boolean;
   readonly tags: string[];
diff --git a/packages/react/src/hooks/notebook.ts b/packages/react/src/hooks/notebook.ts
index 1a8a2831..162e3275 100644
--- a/packages/react/src/hooks/notebook.ts
+++ b/packages/react/src/hooks/notebook.ts
@@ -1,20 +1,14 @@
 import { createRef, useEffect, useState } from 'react';
-import {
-  type ThebeNotebook,
-  type ThebeSession,
-  type IThebeCell,
-  type IThebeCellExecuteReturn,
-  ThebePassiveManager,
-  WIDGET_VIEW_MIMETYPE,
-  WIDGET_STATE_MIMETYPE,
-} from 'thebe-core';
+import type { ThebeNotebook, ThebeSession, IThebeCell, IThebeCellExecuteReturn } from 'thebe-core';
 import { useThebeConfig } from '../ThebeServerProvider';
 import { useThebeLoader } from '../ThebeLoaderProvider';
-import type { IExecuteResult, INotebookContent } from '@jupyterlab/nbformat';
+import type { INotebookContent } from '@jupyterlab/nbformat';
 import { useThebeSession } from '../ThebeSessionProvider';
 import { useRenderMimeRegistry } from '../ThebeRenderMimeRegistryProvider';
 import type { IManagerState } from '@jupyter-widgets/base-manager';
 
+export const WIDGET_STATE_MIMETYPE = 'application/vnd.jupyter.widget-state+json';
+
 export interface NotebookExecuteOptions {
   stopOnError?: boolean;
   before?: () => void;
@@ -168,7 +162,7 @@ export function useNotebook(
       })
       .then((nb: ThebeNotebook) => {
         const cells = opts?.refsForWidgetsOnly ? nb?.widgets ?? [] : nb?.cells ?? [];
-        const manager = new ThebePassiveManager(rendermime);
+        const manager = new core.ThebePassiveManager(rendermime);
         if (nb.metadata.widgets && (nb.metadata.widgets as any)[WIDGET_STATE_MIMETYPE]) {
           manager.load_state((nb.metadata.widgets as any)[WIDGET_STATE_MIMETYPE] as IManagerState);
         }