diff --git a/web/calendar/entry.react.js b/web/calendar/entry.react.js
--- a/web/calendar/entry.react.js
+++ b/web/calendar/entry.react.js
@@ -388,10 +388,7 @@
           this.clearModal();
         };
         this.props.setModal(
-          <ConcurrentModificationModal
-            onClose={this.clearModal}
-            onRefresh={onRefresh}
-          />,
+          <ConcurrentModificationModal onRefresh={onRefresh} />,
         );
       }
       throw e;
diff --git a/web/modals/concurrent-modification-modal.react.js b/web/modals/concurrent-modification-modal.react.js
--- a/web/modals/concurrent-modification-modal.react.js
+++ b/web/modals/concurrent-modification-modal.react.js
@@ -1,18 +1,22 @@
 // @flow
 
+import invariant from 'invariant';
 import * as React from 'react';
 
 import css from '../style.css';
+import { ModalContext } from './modal-provider.react';
 import Modal from './modal.react';
 
 type Props = {
   +onRefresh: () => void,
-  +onClose: () => void,
 };
 
 export default function ConcurrentModificationModal(props: Props): React.Node {
+  const modalContext = React.useContext(ModalContext);
+  invariant(modalContext, 'modalContext not set');
+
   return (
-    <Modal name="Concurrent modification" clearModal={props.onClose}>
+    <Modal name="Concurrent modification" clearModal={modalContext.clearModal}>
       <div className={css['modal-body']}>
         <p>
           It looks like somebody is attempting to modify that field at the same