diff --git a/src/main/java/net/slqmy/template_paper_plugin/data/player/PlayerDataManager.java b/src/main/java/net/slqmy/template_paper_plugin/data/player/PlayerDataManager.java
index d9b4d35f..8f97f1f2 100644
--- a/src/main/java/net/slqmy/template_paper_plugin/data/player/PlayerDataManager.java
+++ b/src/main/java/net/slqmy/template_paper_plugin/data/player/PlayerDataManager.java
@@ -19,6 +19,8 @@ public class PlayerDataManager {
 
   private final TemplatePaperPlugin plugin;
 
+  private final String playerDataFilesExtension = ".json";
+
   private final String playerDataFolderName = "player-data";
   private final String playerDataFolderPath;
   private final File playerDataFolder;
@@ -79,7 +81,7 @@ public void save() {
       UUID uuid = entry.getKey();
       PlayerProfile profile = entry.getValue();
 
-      File file = new File(playerDataFolderPath + File.separator + uuid.toString() + ".json");
+      File file = new File(playerDataFolderPath + File.separator + uuid.toString() + playerDataFilesExtension);
 
       FileWriter writer;
 
diff --git a/src/main/java/net/slqmy/template_paper_plugin/file/FileUtil.java b/src/main/java/net/slqmy/template_paper_plugin/file/FileUtil.java
index 1533bf9b..c59892ac 100644
--- a/src/main/java/net/slqmy/template_paper_plugin/file/FileUtil.java
+++ b/src/main/java/net/slqmy/template_paper_plugin/file/FileUtil.java
@@ -19,10 +19,16 @@ public class FileUtil {
 
   private static final String FILE_EXTENSION_SEPARATOR = ".";
 
+  private static final String FILE_MIME_TYPE_TYPE_SUBTYPE_SEPARATOR = "/";
+
   public static String getFileExtensionSeparator() {
     return FILE_EXTENSION_SEPARATOR;
   }
 
+  public static String getFileMimeTypeTypeSubtypeSeparator() {
+    return FILE_MIME_TYPE_TYPE_SUBTYPE_SEPARATOR;
+  }
+
   public static List<String> getResourceFileFolderResourceFilePaths(String resourceFileFolderPath) throws IOException {
     ClassLoader classLoader = FileUtil.class.getClassLoader();
 
diff --git a/src/main/java/net/slqmy/template_paper_plugin/language/LanguageManager.java b/src/main/java/net/slqmy/template_paper_plugin/language/LanguageManager.java
index 9cf26c5a..4170bc6f 100644
--- a/src/main/java/net/slqmy/template_paper_plugin/language/LanguageManager.java
+++ b/src/main/java/net/slqmy/template_paper_plugin/language/LanguageManager.java
@@ -25,6 +25,8 @@ public class LanguageManager {
 
   private final TemplatePaperPlugin plugin;
 
+  private final String languageMessageFilesExtension = ".yaml";
+
   private final String languagesFolderName = "languages";
   private final String languagesFolderPath;
   private final File languagesFolder;
@@ -62,7 +64,7 @@ private void loadLanguageMessages() {
     for (File languageMessagesFile : languagesFolder.listFiles()) {
       String languageName = languageMessagesFile.getName().split("\\.", 2)[0];
 
-      String languageMessagesResourcePath = languagesFolderName + File.separator + languageName + ".yaml";
+      String languageMessagesResourcePath = languagesFolderName + File.separator + languageName + languageMessageFilesExtension;
       plugin.saveResource(languageMessagesResourcePath, false);
 
       YamlConfiguration messagesConfiguration = YamlConfiguration.loadConfiguration(languageMessagesFile);
diff --git a/src/main/java/net/slqmy/template_paper_plugin/resource_pack/ResourcePackManager.java b/src/main/java/net/slqmy/template_paper_plugin/resource_pack/ResourcePackManager.java
index de8f326c..c588a3a9 100644
--- a/src/main/java/net/slqmy/template_paper_plugin/resource_pack/ResourcePackManager.java
+++ b/src/main/java/net/slqmy/template_paper_plugin/resource_pack/ResourcePackManager.java
@@ -15,7 +15,7 @@ public class ResourcePackManager {
 
   private final String resourcePackFileType = "application";
   private final String resourcePackFileExtension = "zip";
-  private final String resourcePackFileMimeType = resourcePackFileType + "/" + resourcePackFileExtension;
+  private final String resourcePackFileMimeType = resourcePackFileType + FileUtil.getFileMimeTypeTypeSubtypeSeparator() + resourcePackFileExtension;
 
   private String resourcePackZipFilePath;
   private File resourcePackZipFile;