diff --git a/ptscs/ruleset.xml b/ptscs/ruleset.xml
index 4be12f1..62b6c86 100644
--- a/ptscs/ruleset.xml
+++ b/ptscs/ruleset.xml
@@ -204,6 +204,7 @@
     <rule ref="SlevomatCodingStandard.TypeHints.ReturnTypeHint.UselessAnnotation" />
     <rule ref="SlevomatCodingStandard.TypeHints.ParameterTypeHint.UselessAnnotation" />
 
+    <rule ref="SlevomatCodingStandard.Operators.DisallowEqualOperators" />
 
     <!--++++++++++++++++++++++++++++++++++++
     Code analysis
diff --git a/tests/Sniffs/Slevomat/Operators/DisallowEqualOperatorsTest.php b/tests/Sniffs/Slevomat/Operators/DisallowEqualOperatorsTest.php
new file mode 100644
index 0000000..7fbfdaa
--- /dev/null
+++ b/tests/Sniffs/Slevomat/Operators/DisallowEqualOperatorsTest.php
@@ -0,0 +1,19 @@
+<?php declare(strict_types=1);
+
+namespace Ptscs\Tests\Sniffs\Slevomat\Operators;
+
+use Iterator;
+use Ptscs\Tests\SniffTestCase;
+use Ptscs\Tests\Utils\ErrorData;
+
+final class DisallowEqualOperatorsTest extends SniffTestCase
+{
+    public static function provideTestData(): Iterator
+    {
+        yield[
+          [
+            new ErrorData(5, 'SlevomatCodingStandard.Operators.DisallowEqualOperators.DisallowedEqualOperator'),
+          ],
+        ];
+    }
+}
diff --git a/tests/Sniffs/Slevomat/Operators/_data/DisallowEqualOperators.php.fixed b/tests/Sniffs/Slevomat/Operators/_data/DisallowEqualOperators.php.fixed
new file mode 100644
index 0000000..3336041
--- /dev/null
+++ b/tests/Sniffs/Slevomat/Operators/_data/DisallowEqualOperators.php.fixed
@@ -0,0 +1,7 @@
+<?php declare(strict_types=1);
+
+$a = null;
+
+if ($a === '' || $a !== null) {
+    $a = 0;
+}
diff --git a/tests/Sniffs/Slevomat/Operators/_data/DisallowEqualOperators.php.inc b/tests/Sniffs/Slevomat/Operators/_data/DisallowEqualOperators.php.inc
new file mode 100644
index 0000000..81a661a
--- /dev/null
+++ b/tests/Sniffs/Slevomat/Operators/_data/DisallowEqualOperators.php.inc
@@ -0,0 +1,7 @@
+<?php declare(strict_types=1);
+
+$a = null;
+
+if ($a == '' || $a != null) {
+    $a = 0;
+}