diff --git a/src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/__tests__/render.test.js b/src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/__tests__/render.test.js
index 16da9009f5d5fb..9ef4a3e38ee9bb 100644
--- a/src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/__tests__/render.test.js
+++ b/src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/__tests__/render.test.js
@@ -22,6 +22,12 @@ const unmountComponentAtNode = jest.fn();
 
 jest.doMock('react-dom', () => ({ render, unmountComponentAtNode }));
 
+// If we don't mock this, Jest fails with the error `TypeError: Cannot redefine property: prototype
+// at Function.defineProperties`.
+jest.mock('ui/index_patterns', () => ({
+  INDEX_PATTERN_ILLEGAL_CHARACTERS: ['\\', '/', '?', '"', '<', '>', '|', ' '],
+}));
+
 jest.mock('ui/chrome', () => ({
   getUiSettingsClient: () => ({
     get: () => '',
diff --git a/src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/components/step_index_pattern/__tests__/step_index_pattern.test.js b/src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/components/step_index_pattern/__tests__/step_index_pattern.test.js
index 3b05ec4b71ec47..37df9762b54df8 100644
--- a/src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/components/step_index_pattern/__tests__/step_index_pattern.test.js
+++ b/src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/components/step_index_pattern/__tests__/step_index_pattern.test.js
@@ -26,6 +26,12 @@ jest.mock('../../../lib/ensure_minimum_time', () => ({
   ensureMinimumTime: async (promises) => Array.isArray(promises) ? await Promise.all(promises) : await promises
 }));
 
+// If we don't mock this, Jest fails with the error `TypeError: Cannot redefine property: prototype
+// at Function.defineProperties`.
+jest.mock('ui/index_patterns', () => ({
+  INDEX_PATTERN_ILLEGAL_CHARACTERS: ['\\', '/', '?', '"', '<', '>', '|', ' '],
+}));
+
 jest.mock('ui/chrome', () => ({
   getUiSettingsClient: () => ({
     get: () => '',
diff --git a/src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/components/step_index_pattern/step_index_pattern.js b/src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/components/step_index_pattern/step_index_pattern.js
index bf6468c3bf15ba..133154de526191 100644
--- a/src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/components/step_index_pattern/step_index_pattern.js
+++ b/src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/components/step_index_pattern/step_index_pattern.js
@@ -19,10 +19,11 @@
 
 import React, { Component } from 'react';
 import PropTypes from 'prop-types';
-import { ILLEGAL_CHARACTERS, MAX_SEARCH_SIZE } from '../../constants';
+import { INDEX_PATTERN_ILLEGAL_CHARACTERS as ILLEGAL_CHARACTERS } from 'ui/index_patterns';
+import { MAX_SEARCH_SIZE } from '../../constants';
 import {
   getIndices,
-  containsInvalidCharacters,
+  containsIllegalCharacters,
   getMatchedIndices,
   canAppendWildcard,
   ensureMinimumTime
@@ -240,7 +241,7 @@ export class StepIndexPatternComponent extends Component {
       // This is an error scenario but do not report an error
       containsErrors = true;
     }
-    else if (!containsInvalidCharacters(query, ILLEGAL_CHARACTERS)) {
+    else if (containsIllegalCharacters(query, ILLEGAL_CHARACTERS)) {
       const errorMessage = intl.formatMessage(
         {
           id: 'kbn.management.createIndexPattern.step.invalidCharactersErrorMessage',
diff --git a/src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/constants/index.js b/src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/constants/index.js
index 79bdbaed0d7328..86246903b44409 100644
--- a/src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/constants/index.js
+++ b/src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/constants/index.js
@@ -26,4 +26,3 @@ export const MAX_NUMBER_OF_MATCHING_INDICES = 100;
 export const MAX_SEARCH_SIZE = MAX_NUMBER_OF_MATCHING_INDICES + ESTIMATED_NUMBER_OF_SYSTEM_INDICES;
 
 export const PER_PAGE_INCREMENTS = [5, 10, 20, 50];
-export const ILLEGAL_CHARACTERS = ['\\', '/', '?', '"', '<', '>', '|', ' '];
diff --git a/src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/lib/__tests__/contains_invalid_characters.test.js b/src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/lib/__tests__/contains_invalid_characters.test.js
index 2385f3baec6bc4..05c4aba2571bd0 100644
--- a/src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/lib/__tests__/contains_invalid_characters.test.js
+++ b/src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/lib/__tests__/contains_invalid_characters.test.js
@@ -17,16 +17,16 @@
  * under the License.
  */
 
-import { containsInvalidCharacters } from '../contains_invalid_characters';
+import { containsIllegalCharacters } from '../contains_illegal_characters';
 
-describe('containsInvalidCharacters', () => {
-  it('should fail with illegal characters', () => {
-    const valid = containsInvalidCharacters('abc', ['a']);
-    expect(valid).toBeFalsy();
+describe('containsIllegalCharacters', () => {
+  it('returns true with illegal characters', () => {
+    const isInvalid = containsIllegalCharacters('abc', ['a']);
+    expect(isInvalid).toBe(true);
   });
 
-  it('should pass with no illegal characters', () => {
-    const valid = containsInvalidCharacters('abc', ['%']);
-    expect(valid).toBeTruthy();
+  it('returns false with no illegal characters', () => {
+    const isInvalid = containsIllegalCharacters('abc', ['%']);
+    expect(isInvalid).toBe(false);
   });
 });
diff --git a/src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/lib/contains_invalid_characters.js b/src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/lib/contains_illegal_characters.js
similarity index 86%
rename from src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/lib/contains_invalid_characters.js
rename to src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/lib/contains_illegal_characters.js
index 5dbe3d71110616..31485bb3daaa2b 100644
--- a/src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/lib/contains_invalid_characters.js
+++ b/src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/lib/contains_illegal_characters.js
@@ -17,6 +17,6 @@
  * under the License.
  */
 
-export function containsInvalidCharacters(pattern, illegalCharacters) {
-  return !illegalCharacters.some(char => pattern.includes(char));
+export function containsIllegalCharacters(pattern, illegalCharacters) {
+  return illegalCharacters.some(char => pattern.includes(char));
 }
diff --git a/src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/lib/index.js b/src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/lib/index.js
index 22efa498c84ab7..0930eb82514e10 100644
--- a/src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/lib/index.js
+++ b/src/core_plugins/kibana/public/management/sections/indices/create_index_pattern_wizard/lib/index.js
@@ -25,6 +25,6 @@ export { getIndices } from './get_indices';
 
 export { getMatchedIndices } from './get_matched_indices';
 
-export { containsInvalidCharacters } from './contains_invalid_characters';
+export { containsIllegalCharacters } from './contains_illegal_characters';
 
 export { extractTimeFields } from './extract_time_fields';
diff --git a/src/ui/public/index_patterns/constants/index.js b/src/ui/public/index_patterns/constants/index.js
new file mode 100644
index 00000000000000..b22c1682173ca4
--- /dev/null
+++ b/src/ui/public/index_patterns/constants/index.js
@@ -0,0 +1,21 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+export const INDEX_PATTERN_ILLEGAL_CHARACTERS_VISIBLE = ['\\', '/', '?', '"', '<', '>', '|'];
+export const INDEX_PATTERN_ILLEGAL_CHARACTERS = INDEX_PATTERN_ILLEGAL_CHARACTERS_VISIBLE.concat(' ');
diff --git a/src/ui/public/index_patterns/index.js b/src/ui/public/index_patterns/index.js
index 025c0248b08485..5df0b7bb8a6140 100644
--- a/src/ui/public/index_patterns/index.js
+++ b/src/ui/public/index_patterns/index.js
@@ -18,6 +18,12 @@
  */
 
 export { IndexPatternsProvider } from './index_patterns';
+
 export {
   IndexPatternsApiClientProvider,
 } from './index_patterns_api_client_provider';
+
+export {
+  INDEX_PATTERN_ILLEGAL_CHARACTERS,
+  INDEX_PATTERN_ILLEGAL_CHARACTERS_VISIBLE,
+} from './constants';