diff --git a/graylog2-web-interface/src/components/common/Select/PaginatedSelect.test.tsx b/graylog2-web-interface/src/components/common/Select/PaginatedSelect.test.tsx
new file mode 100644
index 0000000000..7c120ab0f3
--- /dev/null
+++ b/graylog2-web-interface/src/components/common/Select/PaginatedSelect.test.tsx
@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2020 Graylog, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the Server Side Public License, version 1,
+ * as published by MongoDB, Inc.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * Server Side Public License for more details.
+ *
+ * You should have received a copy of the Server Side Public License
+ * along with this program. If not, see
+ * <http://www.mongodb.com/licensing/server-side-public-license>.
+ */
+import React from 'react';
+import { render, screen, act } from 'wrappedTestingLibrary';
+import userEvent from '@testing-library/user-event';
+
+import PaginatedSelect from './PaginatedSelect';
+
+const mockOptions = {
+  list: [
+    { label: 'Alpha', value: 'alpha' },
+    { label: 'Beta', value: 'beta' },
+  ],
+  pagination: { page: 1, perPage: 50, query: '' },
+  total: 2,
+};
+
+describe('PaginatedSelect', () => {
+  beforeEach(() => {
+    jest.useFakeTimers();
+  });
+
+  afterEach(() => {
+    jest.useRealTimers();
+  });
+
+  it('should not crash when typing after debounced search fires', async () => {
+    // The debounced handleSearch callback previously returned the Promise from
+    // loadOptions. After the debounce fired, lodash's debounce wrapper would
+    // return that Promise on subsequent calls. react-select treated the
+    // non-null return value as a new inputValue, setting its internal state to
+    // a Promise object, which crashed in trimString() with
+    // "str.replace is not a function".
+    const onLoadOptions = jest.fn(() => Promise.resolve(mockOptions));
+
+    render(
+      <PaginatedSelect
+        placeholder="Pick one"
+        onLoadOptions={onLoadOptions}
+        onChange={() => {}}
+      />,
+    );
+
+    // Wait for initial load
+    await act(() => jest.runAllTimersAsync());
+
+    const input = await screen.findByRole('combobox', { name: 'Pick one' });
+
+    // Type first character — starts the 400ms debounce
+    await userEvent.type(input, 'A', { advanceTimers: jest.advanceTimersByTimeAsync });
+
+    // Fire the debounce so loadOptions runs and the debounced wrapper caches
+    // its Promise return value
+    await act(() => jest.advanceTimersByTimeAsync(500));
+
+    // Type another character — the debounced wrapper now returns the cached
+    // Promise. Before the fix, react-select would use it as inputValue and
+    // crash in trimString().
+    await userEvent.type(input, 'l', { advanceTimers: jest.advanceTimersByTimeAsync });
+
+    await act(() => jest.advanceTimersByTimeAsync(500));
+
+    // If we got here without throwing, the fix works.
+    expect(input).toBeInTheDocument();
+  });
+});
diff --git a/graylog2-web-interface/src/components/common/Select/PaginatedSelect.tsx b/graylog2-web-interface/src/components/common/Select/PaginatedSelect.tsx
index 089ccfc3bf..37ae933df4 100644
--- a/graylog2-web-interface/src/components/common/Select/PaginatedSelect.tsx
+++ b/graylog2-web-interface/src/components/common/Select/PaginatedSelect.tsx
@@ -58,14 +58,10 @@ const PaginatedSelect = ({ onLoadOptions, ...rest }: Props) => {
 
   const handleSearch = debounce((newValue, actionMeta) => {
     if (actionMeta.action === 'input-change') {
-      return loadOptions({ ...DEFAULT_PAGINATION, query: newValue });
+      loadOptions({ ...DEFAULT_PAGINATION, query: newValue });
+    } else if (actionMeta.action === 'menu-close') {
+      loadOptions(DEFAULT_PAGINATION);
     }
-
-    if (actionMeta.action === 'menu-close') {
-      return loadOptions(DEFAULT_PAGINATION);
-    }
-
-    return Promise.resolve();
   }, 400);
 
   const handleLoadMore = debounce(() => {