diff --git a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/painters/RegularPainter.java b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/painters/RegularPainter.java
index aa94a8730..4db6eb0d9 100644
--- a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/painters/RegularPainter.java
+++ b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/painters/RegularPainter.java
@@ -39,6 +39,7 @@ import com.watabou.utils.Rect;
 import com.watabou.utils.Reflection;
 
 import java.util.ArrayList;
+import java.util.HashMap;
 
 public abstract class RegularPainter extends Painter {
 	
@@ -176,6 +177,8 @@ public abstract class RegularPainter extends Painter {
 			hiddenDoorChance = (0.5f + hiddenDoorChance)/2f;
 		}
 
+		roomMerges.clear();
+
 		for (Room r : rooms) {
 			for (Room n : r.connected.keySet()) {
 				
@@ -233,14 +236,28 @@ public abstract class RegularPainter extends Painter {
 			}
 		}
 	}
+
+	private HashMap<Room, Room> roomMerges = new HashMap<>();
 	
 	protected boolean joinRooms( Level l, Room r, Room n ) {
 
-		//FIXME currently this joins rooms a bit too often! Need to think up some limitations
 		if (!(r instanceof StandardRoom) || !((StandardRoom) r).joinable
 				|| !(n instanceof StandardRoom) || !((StandardRoom) n).joinable) {
 			return false;
 		}
+
+		if (roomMerges.get(r) == n) return true;
+		if (roomMerges.get(n) == r) return true;
+
+		//normal sized rooms can be merged at most once. Large and Giant rooms can be merged many times
+		if (roomMerges.containsKey(r) || roomMerges.containsValue(r)){
+			if (((StandardRoom) r).sizeCat == StandardRoom.SizeCategory.NORMAL) return false;
+		}
+		if (roomMerges.containsKey(n) || roomMerges.containsValue(n)){
+			if (((StandardRoom) n).sizeCat == StandardRoom.SizeCategory.NORMAL) return false;
+		}
+
+		//TODO maybe more limitations here, such as limiting maximum width/height for normal sized rooms?
 		
 		Rect w = r.intersect( n );
 		if (w.left == w.right) {
@@ -265,6 +282,8 @@ public abstract class RegularPainter extends Painter {
 			
 			Painter.fill( l, w.left, w.top, w.width(), 1, Terrain.EMPTY );
 		}
+
+		roomMerges.put(r, n);
 		
 		return true;
 	}
diff --git a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/rooms/sewerboss/SewerBossEntranceRoom.java b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/rooms/sewerboss/SewerBossEntranceRoom.java
index 40fa04170..ee4b5673f 100644
--- a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/rooms/sewerboss/SewerBossEntranceRoom.java
+++ b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/rooms/sewerboss/SewerBossEntranceRoom.java
@@ -28,10 +28,6 @@ import com.shatteredpixel.shatteredpixeldungeon.levels.rooms.Room;
 import com.shatteredpixel.shatteredpixeldungeon.levels.rooms.standard.EntranceRoom;
 
 public class SewerBossEntranceRoom extends EntranceRoom {
-
-	{
-		joinable = false;
-	}
 	
 	public void paint(Level level ) {
 		
diff --git a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/rooms/sewerboss/SewerBossExitRoom.java b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/rooms/sewerboss/SewerBossExitRoom.java
index dd895505e..abb85576c 100644
--- a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/rooms/sewerboss/SewerBossExitRoom.java
+++ b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/rooms/sewerboss/SewerBossExitRoom.java
@@ -33,10 +33,6 @@ import com.watabou.noosa.Tilemap;
 import com.watabou.utils.Point;
 
 public class SewerBossExitRoom extends ExitRoom {
-
-	{
-		joinable = false;
-	}
 	
 	@Override
 	public int minWidth() {
diff --git a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/rooms/standard/BlacksmithRoom.java b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/rooms/standard/BlacksmithRoom.java
index b3252bae0..9dde10fd0 100644
--- a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/rooms/standard/BlacksmithRoom.java
+++ b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/rooms/standard/BlacksmithRoom.java
@@ -31,10 +31,6 @@ import com.watabou.utils.Point;
 import com.watabou.utils.Random;
 
 public class BlacksmithRoom extends StandardRoom {
-
-	{
-		joinable = false; //TODO maybe joinable? Could be neat in terms of layout
-	}
 	
 	@Override
 	public int minWidth() {
diff --git a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/rooms/standard/BurnedRoom.java b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/rooms/standard/BurnedRoom.java
index 262ea8590..4a580d538 100644
--- a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/rooms/standard/BurnedRoom.java
+++ b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/rooms/standard/BurnedRoom.java
@@ -29,6 +29,10 @@ import com.watabou.utils.Point;
 import com.watabou.utils.Random;
 
 public class BurnedRoom extends PatchRoom {
+
+	{
+		joinable = false;
+	}
 	
 	@Override
 	public float[] sizeCatProbs() {
diff --git a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/rooms/standard/EntranceRoom.java b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/rooms/standard/EntranceRoom.java
index 6fa625330..b89322127 100644
--- a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/rooms/standard/EntranceRoom.java
+++ b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/rooms/standard/EntranceRoom.java
@@ -33,7 +33,9 @@ import com.watabou.utils.Random;
 
 public class EntranceRoom extends StandardRoom {
 
-	//TODO maybe not joinable? It's a little BS to spawn with enemies
+	{
+		joinable = false;
+	}
 	
 	@Override
 	public int minWidth() {
diff --git a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/rooms/standard/ExitRoom.java b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/rooms/standard/ExitRoom.java
index 54e475c50..6326cea8b 100644
--- a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/rooms/standard/ExitRoom.java
+++ b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/rooms/standard/ExitRoom.java
@@ -28,8 +28,6 @@ import com.shatteredpixel.shatteredpixeldungeon.levels.rooms.Room;
 import com.watabou.utils.Point;
 
 public class ExitRoom extends StandardRoom {
-
-	//TODO maybe not joinable?
 	
 	@Override
 	public int minWidth() {
diff --git a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/rooms/standard/MinefieldRoom.java b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/rooms/standard/MinefieldRoom.java
index 7639f323a..999d5f194 100644
--- a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/rooms/standard/MinefieldRoom.java
+++ b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/rooms/standard/MinefieldRoom.java
@@ -30,6 +30,10 @@ import com.watabou.utils.Random;
 
 public class MinefieldRoom extends StandardRoom {
 
+	{
+		joinable = false;
+	}
+
 	@Override
 	public float[] sizeCatProbs() {
 		return new float[]{4, 1, 0};