diff --git a/src/Package/Package.php b/src/Package/Package.php
index c5fcebd..0cfdaf9 100644
--- a/src/Package/Package.php
+++ b/src/Package/Package.php
@@ -38,7 +38,8 @@ class Package
     /**
      * Package descriptor file
      */
-    private const PACKAGE_DESCRIPTOR_FILE = "package.omp";
+    private const PACKAGE_DESCRIPTOR_FILE_LEAGACY = "package.omp";
+    private const PACKAGE_DESCRIPTOR_FILE = "modpack.xml";
 
     private PackageXML $packageXML;
     protected string $packageArchiveFile;
@@ -92,7 +93,7 @@ public function createRemotePackageDescriptor(): RemotePackageDescriptor
         $xml->preserveWhiteSpace = false;
 
         //create remote root element
-        $remote = $xml->createElement(RemotePackageDescriptor::TAG_REMOTE);
+        $remote = $xml->createElement(RemotePackageDescriptor::TAG_MOD);
         $remote->setAttribute(RemotePackageDescriptor::ATTRIBUTE_IDENT, $this->packageXML->getIdentifier());
         $remote->setAttribute(RemotePackageDescriptor::ATTRIBUTE_FILE, $this->packageArchiveFile);
         $remote->setAttribute(RemotePackageDescriptor::ATTRIBUTE_BYTES, $this->packageByteSize);
@@ -119,7 +120,7 @@ public function createRemotePackageDescriptor(): RemotePackageDescriptor
             // Crop & Resize logo to max 128x128 pixels in size
             $thumbnail = PackageHelper::createThumbnail($this->logoImageData);
 
-            $picture = $xml->createElement(RemotePackageDescriptor::TAG_PICTURE, PackageHelper::encodePackageLogo($thumbnail));
+            $picture = $xml->createElement(RemotePackageDescriptor::TAG_MOD_PICTURE, PackageHelper::encodePackageLogo($thumbnail));
             $remote->appendChild($picture);
          }
 
@@ -170,9 +171,14 @@ protected function retrieveInformationFromArchive(string $packageArchiveFilePath
         // read package descriptor contents
         $packageDescriptorData = $packageZip->getFromName(self::PACKAGE_DESCRIPTOR_FILE);
         if ($packageDescriptorData === false) {
-            throw new Exception(
-                "OMM Package Descriptor (" . self::PACKAGE_DESCRIPTOR_FILE . ") not found or invalid in" . $packageArchiveFilePath
-            );
+
+            // read package descriptor contents (Legacy Mod package below OMM 1.2.x)
+            $packageDescriptorData = $packageZip->getFromName(self::PACKAGE_DESCRIPTOR_FILE_LEAGACY);
+            if ($packageDescriptorData === false) {
+                throw new Exception(
+                    "OMM Package Descriptor (" . self::PACKAGE_DESCRIPTOR_FILE_LEAGACY . " or " . self::PACKAGE_DESCRIPTOR_FILE .") not found or invalid in" . $packageArchiveFilePath
+                );
+            }
         }
 
         // load package XML from the descriptor file
diff --git a/src/Repository/RemotePackageDescriptor.php b/src/Repository/RemotePackageDescriptor.php
index 106f9fd..fef9e97 100644
--- a/src/Repository/RemotePackageDescriptor.php
+++ b/src/Repository/RemotePackageDescriptor.php
@@ -34,8 +34,8 @@ class RemotePackageDescriptor
      * Tags of the remote package descriptor
      */
     public const
-        TAG_REMOTE = "remote",
-        TAG_PICTURE = "picture",
+        TAG_MOD = "mod",
+        TAG_MOD_PICTURE = "thumbnail",
         TAG_DESCRIPTION = "description",
         TAG_URL = "url";
     /**
@@ -46,7 +46,7 @@ class RemotePackageDescriptor
         ATTRIBUTE_FILE = "file",
         ATTRIBUTE_BYTES = "bytes",
         ATTRIBUTE_MD5 = "md5sum",
-        ATTRIBUTE_CHECKSUM = "checksum",
+        ATTRIBUTE_CHECKSUM = "xxhsum",
         ATTRIBUTE_CATEGORY = "category";
 
     /**
@@ -64,7 +64,7 @@ class RemotePackageDescriptor
     public function __construct(DOMElement $remoteXMLElement)
     {
 
-        if($remoteXMLElement->nodeName != self::TAG_REMOTE){
+        if($remoteXMLElement->nodeName != self::TAG_MOD){
             throw new InvalidArgumentException("Passed remote xml element is not valid");
         }
 
diff --git a/src/Repository/RemoteRepositoryXML.php b/src/Repository/RemoteRepositoryXML.php
index c011adc..d2ceb34 100644
--- a/src/Repository/RemoteRepositoryXML.php
+++ b/src/Repository/RemoteRepositoryXML.php
@@ -41,7 +41,7 @@ class RemoteRepositoryXML
         TAG_UUID = "uuid",
         TAG_TITLE = "title",
         TAG_DOWNPATH = "downpath",
-        TAG_REMOTES = "remotes";
+        TAG_REFERENCES = "references";
 
     /**
      * Attributes of the remote repository xml
@@ -144,9 +144,9 @@ protected function updateRepositoryFromXMLData(string $repositoryTitle, string $
         }
 
         // add remote package element and store it for later modification
-        $remotesList = $this->root->getElementsByTagName(self::TAG_REMOTES);
+        $remotesList = $this->root->getElementsByTagName(self::TAG_REFERENCES);
         if ($remotesList->length == 0) {
-            $this->remotes = $this->xml->createElement(self::TAG_REMOTES);
+            $this->remotes = $this->xml->createElement(self::TAG_REFERENCES);
             $this->remotes->setAttribute(self::ATTRIBUTE_COUNT, 0);
             $this->root->appendChild($this->remotes);
 
diff --git a/src/Task/GenerateFolderRepositoryTask.php b/src/Task/GenerateFolderRepositoryTask.php
index 8ff3e73..199683a 100644
--- a/src/Task/GenerateFolderRepositoryTask.php
+++ b/src/Task/GenerateFolderRepositoryTask.php
@@ -228,8 +228,9 @@ private static function getAvailableArchives($searchDir, bool $recursive): array
             }
             else
             {
-                // skip non zip archives
-                if (strcasecmp("zip", pathinfo($fileEntry, PATHINFO_EXTENSION)) != 0) {
+                // skip non zip archives or ozd archives
+                if (strcasecmp("zip", pathinfo($fileEntry, PATHINFO_EXTENSION)) != 0
+                  && strcasecmp("ozp", pathinfo($fileEntry, PATHINFO_EXTENSION)) != 0) {
                     continue;
                 }