diff --git a/DEVELOPER_GUIDE.md b/DEVELOPER_GUIDE.md
index 6f615d3e..11f396c4 100644
--- a/DEVELOPER_GUIDE.md
+++ b/DEVELOPER_GUIDE.md
@@ -36,6 +36,14 @@ The integration tests are using by default following address `https://admin:admi
 
 To run the integration tests, you can use `composer run integration`
 
+```bash
+export OPENSEARCH_PASSWORD=myStrongPassword123!
+export OPENSEARCH_URL=https://admin:$OPENSEARCH_PASSWORD@localhost:9200
+
+composer run integration
+```
+
+
 ### Static analyse and code style checker
 
 The project uses PhpStan for static analyse and php-cs-fixer for code style checker. You can use both tools with following codes
diff --git a/tests/Endpoints/MlNamespaceIntegrationTest.php b/tests/Endpoints/MlNamespaceIntegrationTest.php
index 61962d88..6c10335a 100644
--- a/tests/Endpoints/MlNamespaceIntegrationTest.php
+++ b/tests/Endpoints/MlNamespaceIntegrationTest.php
@@ -30,7 +30,7 @@ public function testRegisterModelGroup()
     {
         $client = Utility::getClient();
 
-        if (!Utility::isOpenSearchVersionAtLeast($client, '2.8.0') || !Utility::isOpenSearchVersionAtmost($client, '2.x')) {
+        if (!Utility::isOpenSearchVersionAtLeast($client, '2.8.0')) {
             $this->markTestSkipped('Ml plugin tests require OpenSearch >= 2.8.0');
         }
 
@@ -47,7 +47,7 @@ public function testgetModels()
     {
         $client = Utility::getClient();
 
-        if (!Utility::isOpenSearchVersionAtLeast($client, '2.12.0') || !Utility::isOpenSearchVersionAtmost($client, '2.x')) {
+        if (!Utility::isOpenSearchVersionAtLeast($client, '2.12.0')) {
             $this->markTestSkipped('Ml plugin tests require OpenSearch >= 2.12.0');
         }
 
@@ -59,7 +59,7 @@ public function testsearchModels()
     {
         $client = Utility::getClient();
 
-        if (!Utility::isOpenSearchVersionAtLeast($client, '2.12.0') || !Utility::isOpenSearchVersionAtmost($client, '2.x')) {
+        if (!Utility::isOpenSearchVersionAtLeast($client, '2.12.0')) {
             $this->markTestSkipped('Ml plugin tests require OpenSearch >= 2.12.0');
         }
 
diff --git a/tests/Utility.php b/tests/Utility.php
index 8775829a..7ca46e2d 100644
--- a/tests/Utility.php
+++ b/tests/Utility.php
@@ -79,35 +79,7 @@ public static function isOpenSearchVersionAtLeast(Client $client, string $versio
             return false;
         }
         $versionNumber = $versionInfo['number'];
-        return version_compare($versionNumber, $version) >= 0;
-    }
-
-    /**
-     * Check if cluster is OpenSearch and version is less than the specified version.
-     */
-    public static function isOpenSearchVersionAtMost(Client $client, string $version): bool
-    {
-        $versionInfo = self::getVersion($client);
-        $distribution = $versionInfo['distribution'] ?? null;
-        if ($distribution !== 'opensearch') {
-            return false;
-        }
-        $versionNumber = $versionInfo['number'];
-        return version_compare($versionNumber, $version, '<');
-    }
-
-    /**
-     * Check if cluster is Elasticsearch and version is greater than or equal to specified version.
-     */
-    public static function isElasticSearchVersionAtLeast(Client $client, string $version): bool
-    {
-        $versionInfo = self::getVersion($client);
-        $distribution = $versionInfo['distribution'] ?? null;
-        if ($distribution === 'opensearch') {
-            return false;
-        }
-        $versionNumber = $versionInfo['number'];
-        return version_compare($versionNumber, $version) >= 0;
+        return version_compare($versionNumber, $version, '>=');
     }
 
     private static function getVersion(Client $client): array
@@ -137,10 +109,7 @@ public static function cleanUpCluster(Client $client): void
     */
     private static function wipeCluster(Client $client): void
     {
-        if (self::isElasticSearchVersionAtLeast($client, '7.4.0')) {
-            self::deleteAllSLMPolicies($client);
-        }
-
+        self::deleteAllSLMPolicies($client);
         self::wipeSnapshots($client);
         self::wipeDataStreams($client);
         self::wipeAllIndices($client);
@@ -229,12 +198,10 @@ private static function deleteAllSLMPolicies(Client $client): void
     private static function wipeDataStreams(Client $client): void
     {
         try {
-            if (self::isElasticSearchVersionAtLeast($client, '7.9.0')) {
-                $client->indices()->deleteDataStream([
-                    'name' => '*',
-                    'expand_wildcards' => 'all'
-                ]);
-            }
+            $client->indices()->deleteDataStream([
+                'name' => '*',
+                'expand_wildcards' => 'all'
+            ]);
         } catch (OpenSearchException $e) {
             // We hit a version of ES that doesn't understand expand_wildcards, try again without it
             try {
@@ -255,14 +222,10 @@ private static function wipeDataStreams(Client $client): void
      */
     private static function wipeAllIndices(Client $client): void
     {
-        $expand = 'open,closed';
-        if (self::isElasticSearchVersionAtLeast($client, '7.7.0')) {
-            $expand .= ',hidden';
-        }
         try {
             $client->indices()->delete([
                 'index' => '*,-.ds-ilm-history-*',
-                'expand_wildcards' => $expand
+                'expand_wildcards' => 'open,closed,hidden'
             ]);
         } catch (Exception $e) {
             if ($e->getCode() != '404') {