diff --git a/launcher/modplatform/atlauncher/ATLPackInstallTask.cpp b/launcher/modplatform/atlauncher/ATLPackInstallTask.cpp
index e5db512e..c4e197b4 100644
--- a/launcher/modplatform/atlauncher/ATLPackInstallTask.cpp
+++ b/launcher/modplatform/atlauncher/ATLPackInstallTask.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright 2020-2021 Jamie Mansfield <jmansfield@cadixdev.org>
+ * Copyright 2020-2022 Jamie Mansfield <jmansfield@cadixdev.org>
  * Copyright 2021 Petr Mrazek <peterix@gmail.com>
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ -357,7 +357,31 @@ bool PackInstallTask::createLibrariesComponent(QString instanceRoot, std::shared
 
 bool PackInstallTask::createPackComponent(QString instanceRoot, std::shared_ptr<PackProfile> profile)
 {
-    if(m_version.mainClass == QString() && m_version.extraArguments == QString()) {
+    if(m_version.mainClass.mainClass.isEmpty() && m_version.extraArguments.arguments.isEmpty()) {
+        return true;
+    }
+
+    auto mainClass = m_version.mainClass.mainClass;
+    auto extraArguments = m_version.extraArguments.arguments;
+
+    auto hasMainClassDepends = !m_version.mainClass.depends.isEmpty();
+    auto hasExtraArgumentsDepends = !m_version.extraArguments.depends.isEmpty();
+    if (hasMainClassDepends || hasExtraArgumentsDepends) {
+        QSet<QString> mods;
+        for (const auto& item : m_version.mods) {
+            mods.insert(item.name);
+        }
+
+        if (hasMainClassDepends && !mods.contains(m_version.mainClass.depends)) {
+            mainClass = "";
+        }
+
+        if (hasExtraArgumentsDepends && !mods.contains(m_version.extraArguments.depends)) {
+            extraArguments = "";
+        }
+    }
+
+    if (mainClass.isEmpty() && extraArguments.isEmpty()) {
         return true;
     }
 
@@ -385,12 +409,12 @@ bool PackInstallTask::createPackComponent(QString instanceRoot, std::shared_ptr<
 
     auto f = std::make_shared<VersionFile>();
     f->name = m_pack + " " + m_version_name;
-    if(m_version.mainClass != QString() && !mainClasses.contains(m_version.mainClass)) {
-        f->mainClass = m_version.mainClass;
+    if(!mainClass.isEmpty() && !mainClasses.contains(mainClass)) {
+        f->mainClass = mainClass;
     }
 
     // Parse out tweakers
-    auto args = m_version.extraArguments.split(" ");
+    auto args = extraArguments.split(" ");
     QString previous;
     for(auto arg : args) {
         if(arg.startsWith("--tweakClass=") || previous == "--tweakClass") {
@@ -703,6 +727,17 @@ bool PackInstallTask::extractMods(
     for (auto iter = toCopy.begin(); iter != toCopy.end(); iter++) {
         auto &from = iter.key();
         auto &to = iter.value();
+
+        // If the file already exists, assume the mod is the correct copy - and remove
+        // the copy from the Configs.zip
+        QFileInfo fileInfo(to);
+        if (fileInfo.exists()) {
+            if (!QFile::remove(to)) {
+                qWarning() << "Failed to delete" << to;
+                return false;
+            }
+        }
+
         FS::copy fileCopyOperation(from, to);
         if(!fileCopyOperation()) {
             qWarning() << "Failed to copy" << from << "to" << to;
diff --git a/launcher/modplatform/atlauncher/ATLPackManifest.cpp b/launcher/modplatform/atlauncher/ATLPackManifest.cpp
index 40be6d53..87c920e1 100644
--- a/launcher/modplatform/atlauncher/ATLPackManifest.cpp
+++ b/launcher/modplatform/atlauncher/ATLPackManifest.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright 2020-2021 Jamie Mansfield <jmansfield@cadixdev.org>
+ * Copyright 2020-2022 Jamie Mansfield <jmansfield@cadixdev.org>
  * Copyright 2021 Petr Mrazek <peterix@gmail.com>
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ -185,6 +185,18 @@ static void loadVersionMod(ATLauncher::VersionMod & p, QJsonObject & obj) {
     p.effectively_hidden = p.hidden || p.library;
 }
 
+static void loadVersionMainClass(ATLauncher::PackVersionMainClass & m, QJsonObject & obj)
+{
+    m.mainClass = Json::ensureString(obj, "mainClass", "");
+    m.depends = Json::ensureString(obj, "depends", "");
+}
+
+static void loadVersionExtraArguments(ATLauncher::PackVersionExtraArguments & a, QJsonObject & obj)
+{
+    a.arguments = Json::ensureString(obj, "arguments", "");
+    a.depends = Json::ensureString(obj, "depends", "");
+}
+
 void ATLauncher::loadVersion(PackVersion & v, QJsonObject & obj)
 {
     v.version = Json::requireString(obj, "version");
@@ -193,12 +205,12 @@ void ATLauncher::loadVersion(PackVersion & v, QJsonObject & obj)
 
     if(obj.contains("mainClass")) {
         auto main = Json::requireObject(obj, "mainClass");
-        v.mainClass = Json::ensureString(main, "mainClass", "");
+        loadVersionMainClass(v.mainClass, main);
     }
 
     if(obj.contains("extraArguments")) {
         auto arguments = Json::requireObject(obj, "extraArguments");
-        v.extraArguments = Json::ensureString(arguments, "arguments", "");
+        loadVersionExtraArguments(v.extraArguments, arguments);
     }
 
     if(obj.contains("loader")) {
diff --git a/launcher/modplatform/atlauncher/ATLPackManifest.h b/launcher/modplatform/atlauncher/ATLPackManifest.h
index 673f2f8b..6be82da4 100644
--- a/launcher/modplatform/atlauncher/ATLPackManifest.h
+++ b/launcher/modplatform/atlauncher/ATLPackManifest.h
@@ -1,5 +1,5 @@
 /*
- * Copyright 2020 Jamie Mansfield <jmansfield@cadixdev.org>
+ * Copyright 2020-2022 Jamie Mansfield <jmansfield@cadixdev.org>
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -122,13 +122,25 @@ struct VersionConfigs
     QString sha1;
 };
 
+struct PackVersionMainClass
+{
+    QString mainClass;
+    QString depends;
+};
+
+struct PackVersionExtraArguments
+{
+    QString arguments;
+    QString depends;
+};
+
 struct PackVersion
 {
     QString version;
     QString minecraft;
     bool noConfigs;
-    QString mainClass;
-    QString extraArguments;
+    PackVersionMainClass mainClass;
+    PackVersionExtraArguments extraArguments;
 
     VersionLoader loader;
     QVector<VersionLibrary> libraries;