diff --git a/src/main/scala/li/cil/oc/server/network/WirelessNetwork.scala b/src/main/scala/li/cil/oc/server/network/WirelessNetwork.scala
index 28da4912a..bf7864728 100644
--- a/src/main/scala/li/cil/oc/server/network/WirelessNetwork.scala
+++ b/src/main/scala/li/cil/oc/server/network/WirelessNetwork.scala
@@ -142,7 +142,7 @@ object WirelessNetwork {
         val y = (origin.yCoord + v.yCoord * rGap + side.yCoord * rSide + top.yCoord * rTop).toInt
         val z = (origin.zCoord + v.zCoord * rGap + side.zCoord * rSide + top.zCoord * rTop).toInt
         val blockPos = BlockPosition(x, y, z, world)
-        Option(world.getBlock(blockPos)) match {
+        if (world.isBlockLoaded(blockPos)) Option(world.getBlock(blockPos)) match {
           case Some(block) => hardness += block.getBlockHardness(blockPos)
           case _ =>
         }
diff --git a/src/main/scala/li/cil/oc/util/ExtendedWorld.scala b/src/main/scala/li/cil/oc/util/ExtendedWorld.scala
index 2733f15bc..63c463a22 100644
--- a/src/main/scala/li/cil/oc/util/ExtendedWorld.scala
+++ b/src/main/scala/li/cil/oc/util/ExtendedWorld.scala
@@ -62,6 +62,8 @@ object ExtendedWorld {
     def setBlockToAir(position: BlockPosition) = world.setBlockToAir(position.toBlockPos)
 
     def isSideSolid(position: BlockPosition, side: EnumFacing) = world.isSideSolid(position.toBlockPos, side)
+
+    def isBlockLoaded(position: BlockPosition) = world.isBlockLoaded(position.toBlockPos)
   }
 
 }