diff --git a/src/net/torvald/terrarum/blockproperties/BlockProp.kt b/src/net/torvald/terrarum/blockproperties/BlockProp.kt
index 27b710a33..bc33afd9f 100644
--- a/src/net/torvald/terrarum/blockproperties/BlockProp.kt
+++ b/src/net/torvald/terrarum/blockproperties/BlockProp.kt
@@ -57,11 +57,12 @@ class BlockProp {
     //var lumColB = 0f // memoised value of dynamic luminosity
     //var lumColA = 0f // memoised value of dynamic luminosity
     internal val _lumCol = Cvec(0)
+    // X- and Y-value must be treated properly beforehand! (use GameWorld.coerceXY())
     fun getLumCol(x: Int, y: Int) = if (dynamicLuminosityFunction == 0) {
         baseLumCol
     } else {
-        val offset = XXHash32.hash(((x and 0xFFFF).shl(16) or (y and 0xFFFF)).toLittle(), 10000)
-        BlockCodex[BlockCodex.dynamicToVirtualMap[id]!! - offset.fmod(BlockCodex.DYNAMIC_RANDOM_CASES)]._lumCol
+        val offset = XXHash32.hash(((x and 0xFFFF).shl(16) or (y and 0xFFFF)).toLittle(), 10000).fmod(BlockCodex.DYNAMIC_RANDOM_CASES)
+        BlockCodex[BlockCodex.dynamicToVirtualMap[id]!! - offset]._lumCol
     }
 
     /**
diff --git a/src/net/torvald/terrarum/gameworld/GameWorld.kt b/src/net/torvald/terrarum/gameworld/GameWorld.kt
index 088128f2b..493465fe2 100644
--- a/src/net/torvald/terrarum/gameworld/GameWorld.kt
+++ b/src/net/torvald/terrarum/gameworld/GameWorld.kt
@@ -170,7 +170,7 @@ open class GameWorld : Disposable {
     //val wireArray: ByteArray
     //    get() = layerWire.data
 
-    private fun coerceXY(x: Int, y: Int) = (x fmod width) to (y.coerceIn(0, height - 1))
+    fun coerceXY(x: Int, y: Int) = (x fmod width) to (y.coerceIn(0, height - 1))
 
     fun getTileFromWall(rawX: Int, rawY: Int): Int {
         val (x, y) = coerceXY(rawX, rawY)
@@ -182,6 +182,9 @@ open class GameWorld : Disposable {
         return layerTerrain.unsafeGetTile(x, y)
     }
 
+    fun getTileFromWallRaw(coercedX: Int, coercedY: Int) = layerWall.unsafeGetTile(coercedX, coercedY)
+    fun getTileFromTerrainRaw(coercedX: Int, coercedY: Int) = layerTerrain.unsafeGetTile(coercedX, coercedY)
+
     /**
      * Set the tile of wall as specified, with damage value of zero.
      * @param x
diff --git a/src/net/torvald/terrarum/realestate/LandUtil.kt b/src/net/torvald/terrarum/realestate/LandUtil.kt
index 46541c21b..b84557e18 100644
--- a/src/net/torvald/terrarum/realestate/LandUtil.kt
+++ b/src/net/torvald/terrarum/realestate/LandUtil.kt
@@ -10,9 +10,11 @@ import net.torvald.terrarum.gameworld.fmod
  * Created by minjaesong on 2016-03-27.
  */
 object LandUtil {
-    fun getBlockAddr(world: GameWorld, x: Int, y: Int): BlockAddress =
-            // coercing and fmod-ing follows ROUNDWORLD rule. See: GameWorld.coerceXY()
-            (world.width * y.coerceIn(0, world.height - 1)).toLong() + x.fmod(world.width)
+    fun getBlockAddr(world: GameWorld, x: Int, y: Int): BlockAddress {
+        // coercing and fmod-ing follows ROUNDWORLD rule. See: GameWorld.coerceXY()
+        val (x, y) = world.coerceXY(x, y)
+        return (world.width.toLong() * y) + x
+    }
 
     fun resolveBlockAddr(world: GameWorld, t: BlockAddress): Pair<Int, Int> =
             Pair((t % world.width).toInt(), (t / world.width).toInt())
diff --git a/src/net/torvald/terrarum/worlddrawer/LightmapRendererNew.kt b/src/net/torvald/terrarum/worlddrawer/LightmapRendererNew.kt
index 6d247066d..199a42801 100644
--- a/src/net/torvald/terrarum/worlddrawer/LightmapRendererNew.kt
+++ b/src/net/torvald/terrarum/worlddrawer/LightmapRendererNew.kt
@@ -674,10 +674,12 @@ object LightmapRenderer {
      * - sunlight
      */
     private fun getLightsAndShades(x: Int, y: Int) {
+        val (x, y) = world.coerceXY(x, y)
+
         lightLevelThis.set(colourNull)
-        thisTerrain = world.getTileFromTerrain(x, y)
+        thisTerrain = world.getTileFromTerrainRaw(x, y)
         thisFluid = world.getFluid(x, y)
-        thisWall = world.getTileFromWall(x, y)
+        thisWall = world.getTileFromWallRaw(x, y)
 
         // regarding the issue #26
         try {