diff --git a/build.gradle b/build.gradle
index 80fc672..5c76755 100755
--- a/build.gradle
+++ b/build.gradle
@@ -26,7 +26,7 @@ teavm.js {
     obfuscated = true
     sourceMap = true
     targetFileName = "../classes.js"
-    optimization = org.teavm.gradle.api.OptimizationLevel.AGGRESSIVE
+    optimization = org.teavm.gradle.api.OptimizationLevel.BALANCED // no fps boost was observed with "AGGRESSIVE"
     outOfProcess = false
     fastGlobalAnalysis = false
     processMemory = 512
diff --git a/src/main/java/net/lax1dude/eaglercraft/v1_8/EaglercraftVersion.java b/src/main/java/net/lax1dude/eaglercraft/v1_8/EaglercraftVersion.java
index 4a4b000..30f1d4c 100755
--- a/src/main/java/net/lax1dude/eaglercraft/v1_8/EaglercraftVersion.java
+++ b/src/main/java/net/lax1dude/eaglercraft/v1_8/EaglercraftVersion.java
@@ -10,7 +10,7 @@ public class EaglercraftVersion {
 	/// Customize these to fit your fork:
 	
 	public static final String projectForkName = "EaglercraftX";
-	public static final String projectForkVersion = "u24";
+	public static final String projectForkVersion = "u25";
 	public static final String projectForkVendor = "lax1dude";
 	
 	public static final String projectForkURL = "https://gitlab.com/lax1dude/eaglercraftx-1.8";
@@ -20,7 +20,7 @@ public class EaglercraftVersion {
 	public static final String projectOriginName = "EaglercraftX";
 	public static final String projectOriginAuthor = "lax1dude";
 	public static final String projectOriginRevision = "1.8";
-	public static final String projectOriginVersion = "u24";
+	public static final String projectOriginVersion = "u25";
 	
 	public static final String projectOriginURL = "https://gitlab.com/lax1dude/eaglercraftx-1.8"; // rest in peace
 	
@@ -31,7 +31,7 @@ public class EaglercraftVersion {
 	public static final boolean enableUpdateService = true;
 
 	public static final String updateBundlePackageName = "net.lax1dude.eaglercraft.v1_8.client";
-	public static final int updateBundlePackageVersionInt = 24;
+	public static final int updateBundlePackageVersionInt = 25;
 
 	public static final String updateLatestLocalStorageKey = "latestUpdate_" + updateBundlePackageName;
 
diff --git a/src/main/java/net/lax1dude/eaglercraft/v1_8/sp/server/EaglerIntegratedServerWorker.java b/src/main/java/net/lax1dude/eaglercraft/v1_8/sp/server/EaglerIntegratedServerWorker.java
index 3d55e43..a5ec595 100755
--- a/src/main/java/net/lax1dude/eaglercraft/v1_8/sp/server/EaglerIntegratedServerWorker.java
+++ b/src/main/java/net/lax1dude/eaglercraft/v1_8/sp/server/EaglerIntegratedServerWorker.java
@@ -257,7 +257,11 @@ public class EaglerIntegratedServerWorker {
 			case IPCPacket0ASetWorldDifficulty.ID: {
 				IPCPacket0ASetWorldDifficulty pkt = (IPCPacket0ASetWorldDifficulty)ipc;
 				if(!isServerStopped()) {
-					currentProcess.setDifficultyForAllWorlds(EnumDifficulty.getDifficultyEnum(pkt.difficulty));
+					if(pkt.difficulty == (byte)-1) {
+						currentProcess.setDifficultyLockedForAllWorlds(true);
+					}else {
+						currentProcess.setDifficultyForAllWorlds(EnumDifficulty.getDifficultyEnum(pkt.difficulty));
+					}
 				}else {
 					logger.warn("Client tried to set difficulty while server was stopped");
 				}
diff --git a/src/main/java/net/minecraft/client/gui/GuiOptions.java b/src/main/java/net/minecraft/client/gui/GuiOptions.java
index 6745e57..b020d50 100755
--- a/src/main/java/net/minecraft/client/gui/GuiOptions.java
+++ b/src/main/java/net/minecraft/client/gui/GuiOptions.java
@@ -140,6 +140,7 @@ public class GuiOptions extends GuiScreen implements GuiYesNoCallback {
 		this.mc.displayGuiScreen(this);
 		if (i == 109 && flag && this.mc.theWorld != null) {
 			this.mc.theWorld.getWorldInfo().setDifficultyLocked(true);
+			SingleplayerServerController.setDifficulty(-1);
 			this.field_175356_r.func_175229_b(true);
 			this.field_175356_r.enabled = false;
 			this.field_175357_i.enabled = false;
diff --git a/src/main/java/net/minecraft/network/play/server/S41PacketServerDifficulty.java b/src/main/java/net/minecraft/network/play/server/S41PacketServerDifficulty.java
index 4cd795d..45dceca 100755
--- a/src/main/java/net/minecraft/network/play/server/S41PacketServerDifficulty.java
+++ b/src/main/java/net/minecraft/network/play/server/S41PacketServerDifficulty.java
@@ -50,14 +50,16 @@ public class S41PacketServerDifficulty implements Packet<INetHandlerPlayClient>
 	 * Reads the raw packet data from the data stream.
 	 */
 	public void readPacketData(PacketBuffer parPacketBuffer) throws IOException {
-		this.difficulty = EnumDifficulty.getDifficultyEnum(parPacketBuffer.readUnsignedByte());
+		int i = parPacketBuffer.readUnsignedByte();
+		this.difficulty = EnumDifficulty.getDifficultyEnum(i & 3);
+		this.difficultyLocked = (i & 4) != 0;
 	}
 
 	/**+
 	 * Writes the raw packet data to the data stream.
 	 */
 	public void writePacketData(PacketBuffer parPacketBuffer) throws IOException {
-		parPacketBuffer.writeByte(this.difficulty.getDifficultyId());
+		parPacketBuffer.writeByte(this.difficulty.getDifficultyId() | (this.difficultyLocked ? 4 : 0));
 	}
 
 	public boolean isDifficultyLocked() {
diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
index cc2ea94..521e5c0 100755
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -23,6 +23,7 @@ import net.minecraft.crash.CrashReport;
 import net.minecraft.entity.Entity;
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.network.play.server.S03PacketTimeUpdate;
+import net.minecraft.network.play.server.S41PacketServerDifficulty;
 import net.minecraft.profiler.Profiler;
 import net.minecraft.server.management.ServerConfigurationManager;
 import net.minecraft.util.BlockPos;
@@ -194,13 +195,12 @@ public abstract class MinecraftServer implements Runnable, ICommandSender, IThre
 			}
 
 			this.worldServers[j].addWorldAccess(new WorldManager(this, this.worldServers[j]));
-			if (!this.isSinglePlayer()) {
-				this.worldServers[j].getWorldInfo().setGameType(this.getGameType());
-			}
 		}
 
 		this.serverConfigManager.setPlayerManager(this.worldServers);
-		this.setDifficultyForAllWorlds(this.getDifficulty());
+		if (this.worldServers[0].getWorldInfo().getDifficulty() == null) {
+			this.setDifficultyForAllWorlds(this.getDifficulty());
+		}
 		this.isSpawnChunksLoaded = this.worldServers[0].getWorldInfo().getGameRulesInstance()
 				.getBoolean("loadSpawnChunks");
 		if (this.isSpawnChunksLoaded) {
@@ -756,6 +756,17 @@ public abstract class MinecraftServer implements Runnable, ICommandSender, IThre
 				}
 			}
 		}
+		this.getConfigurationManager().sendPacketToAllPlayers(new S41PacketServerDifficulty(
+				this.worldServers[0].getDifficulty(), this.worldServers[0].getWorldInfo().isDifficultyLocked()));
+	}
+
+	public void setDifficultyLockedForAllWorlds(boolean locked) {
+		for (int i = 0; i < this.worldServers.length; ++i) {
+			WorldServer worldserver = this.worldServers[i];
+			if (worldserver != null) {
+				worldserver.getWorldInfo().setDifficultyLocked(locked);
+			}
+		}
 
 	}