diff --git a/core/src/io/anuke/mindustry/core/NetServer.java b/core/src/io/anuke/mindustry/core/NetServer.java
index 00653983d0..f73b14d351 100644
--- a/core/src/io/anuke/mindustry/core/NetServer.java
+++ b/core/src/io/anuke/mindustry/core/NetServer.java
@@ -262,6 +262,7 @@ public class NetServer extends Module{
             sync();
         }else if(!closing){
             closing = true;
+            weapons.clear();
             Vars.ui.loadfrag.show("$text.server.closing");
             Timers.runTask(5f, () -> {
                 Net.closeServer();
diff --git a/core/src/io/anuke/mindustry/world/blocks/DistributionBlocks.java b/core/src/io/anuke/mindustry/world/blocks/DistributionBlocks.java
index 2153999a45..9ce3a90efd 100644
--- a/core/src/io/anuke/mindustry/world/blocks/DistributionBlocks.java
+++ b/core/src/io/anuke/mindustry/world/blocks/DistributionBlocks.java
@@ -1,18 +1,17 @@
 package io.anuke.mindustry.world.blocks;
 
 import io.anuke.mindustry.world.Block;
-import io.anuke.mindustry.world.blocks.types.LiquidBlock;
 import io.anuke.mindustry.world.blocks.types.distribution.*;
 
 public class DistributionBlocks{
 	
 	public static final Block
 	
-	conduit = new LiquidBlock("conduit"){{
+	conduit = new Conduit("conduit"){{
 		health = 45;
 	}},
 	
-	pulseconduit = new LiquidBlock("pulseconduit"){{
+	pulseconduit = new Conduit("pulseconduit"){{
 		liquidCapacity = 16f;
 		flowfactor = 4.9f;
 		health = 65;
diff --git a/core/src/io/anuke/mindustry/world/blocks/types/distribution/Conduit.java b/core/src/io/anuke/mindustry/world/blocks/types/distribution/Conduit.java
new file mode 100644
index 0000000000..58ee6f7eef
--- /dev/null
+++ b/core/src/io/anuke/mindustry/world/blocks/types/distribution/Conduit.java
@@ -0,0 +1,16 @@
+package io.anuke.mindustry.world.blocks.types.distribution;
+
+import io.anuke.mindustry.world.Block;
+import io.anuke.mindustry.world.blocks.types.LiquidBlock;
+
+public class Conduit extends LiquidBlock {
+
+    public Conduit(String name) {
+        super(name);
+    }
+
+    @Override
+    public boolean canReplace(Block other) {
+        return other instanceof Conduit && other != this;
+    }
+}
diff --git a/core/src/io/anuke/mindustry/world/blocks/types/distribution/LiquidJunction.java b/core/src/io/anuke/mindustry/world/blocks/types/distribution/LiquidJunction.java
index 829d680be9..427a66f167 100644
--- a/core/src/io/anuke/mindustry/world/blocks/types/distribution/LiquidJunction.java
+++ b/core/src/io/anuke/mindustry/world/blocks/types/distribution/LiquidJunction.java
@@ -5,7 +5,7 @@ import io.anuke.mindustry.world.Tile;
 import io.anuke.mindustry.world.blocks.types.LiquidBlock;
 import io.anuke.ucore.core.Draw;
 
-public class LiquidJunction extends LiquidBlock{
+public class LiquidJunction extends Conduit{
 
 	public LiquidJunction(String name) {
 		super(name);
diff --git a/core/src/io/anuke/mindustry/world/blocks/types/distribution/LiquidRouter.java b/core/src/io/anuke/mindustry/world/blocks/types/distribution/LiquidRouter.java
index 3e6308e6fa..1b26876753 100644
--- a/core/src/io/anuke/mindustry/world/blocks/types/distribution/LiquidRouter.java
+++ b/core/src/io/anuke/mindustry/world/blocks/types/distribution/LiquidRouter.java
@@ -2,10 +2,9 @@ package io.anuke.mindustry.world.blocks.types.distribution;
 
 import io.anuke.mindustry.resource.Liquid;
 import io.anuke.mindustry.world.Tile;
-import io.anuke.mindustry.world.blocks.types.LiquidBlock;
 import io.anuke.ucore.core.Draw;
 
-public class LiquidRouter extends LiquidBlock{
+public class LiquidRouter extends Conduit{
 	protected final int timerDump = timers++;
 
 	public LiquidRouter(String name) {
diff --git a/core/src/io/anuke/mindustry/world/blocks/types/distribution/PowerLaser.java b/core/src/io/anuke/mindustry/world/blocks/types/distribution/PowerLaser.java
index 60ceafe8d1..ba7e09c94b 100644
--- a/core/src/io/anuke/mindustry/world/blocks/types/distribution/PowerLaser.java
+++ b/core/src/io/anuke/mindustry/world/blocks/types/distribution/PowerLaser.java
@@ -1,6 +1,7 @@
 package io.anuke.mindustry.world.blocks.types.distribution;
 
 import com.badlogic.gdx.graphics.Color;
+import io.anuke.mindustry.world.Block;
 import io.anuke.mindustry.world.Tile;
 import io.anuke.mindustry.world.blocks.types.production.Generator;
 
@@ -15,7 +16,12 @@ public class PowerLaser extends Generator{
 		laserDirections = 1;
 		health = 50;
 	}
-	
+
+	@Override
+	public boolean canReplace(Block other) {
+		return other instanceof  PowerLaser && other != this;
+	}
+
 	@Override
 	public void update(Tile tile){
 		distributeLaserPower(tile);