diff --git a/libraries/classes/OpenDocument.php b/libraries/classes/OpenDocument.php
index b2279499fd..697717fb27 100644
--- a/libraries/classes/OpenDocument.php
+++ b/libraries/classes/OpenDocument.php
@@ -16,7 +16,7 @@ use const DATE_W3C;
  */
 class OpenDocument
 {
-    public const NS = <<<EOT
+    public const NS = <<<'EOT'
 xmlns:office="urn:oasis:names:tc:opendocument:xmlns:office:1.0"
 xmlns:text="urn:oasis:names:tc:opendocument:xmlns:text:1.0"
 xmlns:table="urn:oasis:names:tc:opendocument:xmlns:table:1.0"
diff --git a/phpcs.xml.dist b/phpcs.xml.dist
index 722dd13728..5a46ff086f 100644
--- a/phpcs.xml.dist
+++ b/phpcs.xml.dist
@@ -84,9 +84,6 @@
     <rule ref="SlevomatCodingStandard.TypeHints.UnionTypeHintFormat.DisallowedShortNullable">
         <severity>4</severity>
     </rule>
-    <rule ref="SlevomatCodingStandard.PHP.RequireNowdoc.RequiredNowdoc">
-        <severity>4</severity>
-    </rule>
     <rule ref="Squiz.NamingConventions.ValidVariableName.NotCamelCaps">
         <severity>4</severity>
     </rule>
diff --git a/test/classes/ExportTest.php b/test/classes/ExportTest.php
index 7727830770..7c43759a2b 100644
--- a/test/classes/ExportTest.php
+++ b/test/classes/ExportTest.php
@@ -173,7 +173,7 @@ class ExportTest extends AbstractTestCase
             ''
         );
 
-        $expected = <<<SQL
+        $expected = <<<'SQL'
 
 INSERT INTO test_table (id, name, datetimefield) VALUES
 ('1', 'abcd', '2011-01-20 02:00:02'),
@@ -253,7 +253,7 @@ SQL;
             ''
         );
 
-        $expected = <<<SQL
+        $expected = <<<'SQL'
 CREATE DATABASE IF NOT EXISTS test_db DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci;
 USE test_db;