diff --git a/app_pojavlauncher/src/main/assets/components/OptiInst.jar b/app_pojavlauncher/src/main/assets/components/OptiInst.jar
new file mode 100644
index 000000000..94b951bc7
Binary files /dev/null and b/app_pojavlauncher/src/main/assets/components/OptiInst.jar differ
diff --git a/app_pojavlauncher/src/main/java/net/kdt/pojavlaunch/JavaGUILauncherActivity.java b/app_pojavlauncher/src/main/java/net/kdt/pojavlaunch/JavaGUILauncherActivity.java
index 9c1bb7c93..45bd32faa 100644
--- a/app_pojavlauncher/src/main/java/net/kdt/pojavlaunch/JavaGUILauncherActivity.java
+++ b/app_pojavlauncher/src/main/java/net/kdt/pojavlaunch/JavaGUILauncherActivity.java
@@ -172,6 +172,9 @@ public class JavaGUILauncherActivity extends LoggableActivity {
         } else if (InstallerDetector.isFabric(installer)) {
             appendlnToLog("Detected Fabric Installer!");
             return new FabricInstaller(installer).install(this);
+        }else if (InstallerDetector.isOptiFine(installer)) {
+            appendlnToLog("Detected OptiFine Installer!");
+            return new LegacyOptifineInstaller(installer).install(this);
         } else {
             appendlnToLog("No mod detected. Starting JVM");
             isLogAllow = false;
diff --git a/app_pojavlauncher/src/main/java/net/kdt/pojavlaunch/PojavLoginActivity.java b/app_pojavlauncher/src/main/java/net/kdt/pojavlaunch/PojavLoginActivity.java
index 5742501b5..712aba67f 100644
--- a/app_pojavlauncher/src/main/java/net/kdt/pojavlaunch/PojavLoginActivity.java
+++ b/app_pojavlauncher/src/main/java/net/kdt/pojavlaunch/PojavLoginActivity.java
@@ -332,6 +332,8 @@ public class PojavLoginActivity extends BaseActivity
 
             Tools.copyAssetFile(this, "components/ForgeInstallerHeadless/forge-installer-headless-1.0.1.jar",
                 Tools.DIR_GAME_NEW + "/config", "forge-installer-headless.jar", true);
+            Tools.copyAssetFile(this, "components/OptiInst.jar",
+                    Tools.DIR_GAME_NEW + "/config", "OptiInst.jar", true);
             Tools.copyAssetFile(this, "components/security/pro-grade.jar", Tools.DIR_DATA, true);
             Tools.copyAssetFile(this, "components/security/java_sandbox.policy", Tools.DIR_DATA, true);
             Tools.copyAssetFile(this, "options.txt", Tools.DIR_GAME_NEW, false);
diff --git a/app_pojavlauncher/src/main/java/net/kdt/pojavlaunch/installers/InstallerDetector.java b/app_pojavlauncher/src/main/java/net/kdt/pojavlaunch/installers/InstallerDetector.java
index 98af7ac90..154da56fb 100644
--- a/app_pojavlauncher/src/main/java/net/kdt/pojavlaunch/installers/InstallerDetector.java
+++ b/app_pojavlauncher/src/main/java/net/kdt/pojavlaunch/installers/InstallerDetector.java
@@ -1,6 +1,9 @@
 package net.kdt.pojavlaunch.installers;
 
 import java.io.*;
+import java.util.Enumeration;
+import java.util.zip.ZipEntry;
+
 import com.google.gson.*;
 import net.kdt.pojavlaunch.value.*;
 
@@ -9,7 +12,10 @@ public class InstallerDetector
     public static boolean isFabric(BaseInstaller installer) {
         return installer.mJarFile.getEntry("net/fabricmc/installer/Main.class") != null;
     }
-    
+    public static boolean isOptiFine(BaseInstaller installer) {
+        Enumeration e = installer.mJarFile.entries();
+        return installer.mJarFile.getEntry("optifine/Installer.class") != null;
+    }
     // Forge Legacy: for 1.12.1 and below
     public static boolean isForgeLegacy(BaseInstaller installer) throws IOException, JsonSyntaxException {
         ForgeInstallProfile profile = LegacyForgeInstaller.readInstallProfile(installer);
diff --git a/app_pojavlauncher/src/main/java/net/kdt/pojavlaunch/installers/LegacyOptifineInstaller.java b/app_pojavlauncher/src/main/java/net/kdt/pojavlaunch/installers/LegacyOptifineInstaller.java
index 99b316bd2..ced61373d 100644
--- a/app_pojavlauncher/src/main/java/net/kdt/pojavlaunch/installers/LegacyOptifineInstaller.java
+++ b/app_pojavlauncher/src/main/java/net/kdt/pojavlaunch/installers/LegacyOptifineInstaller.java
@@ -17,7 +17,9 @@ public class LegacyOptifineInstaller extends BaseInstaller {
 
     @Override
     public int install(JavaGUILauncherActivity ctx) throws IOException {
-        
-        return 0;
+        mJarFile.close();
+        ctx.appendlnToLog("Launching JVM");
+        return ctx.launchJavaRuntime(null,
+                "-jar "+Tools.DIR_GAME_NEW+"/config/OptiInst.jar " + mFile.getAbsolutePath() +" .");
     }
 }