diff --git a/src/main/scala/li/cil/oc/common/item/data/PrintData.scala b/src/main/scala/li/cil/oc/common/item/data/PrintData.scala
index c3de25d6f..581caca24 100644
--- a/src/main/scala/li/cil/oc/common/item/data/PrintData.scala
+++ b/src/main/scala/li/cil/oc/common/item/data/PrintData.scala
@@ -31,7 +31,7 @@ class PrintData extends ItemData {
   var isBeaconBase = false
   var lightLevel = 0
 
-  def hasActiveState = stateOn.size > 0
+  def hasActiveState = stateOn.nonEmpty
 
   def emitLight = lightLevel > 0
 
@@ -111,7 +111,7 @@ object PrintData {
 
   def computeApproximateOpacity(shapes: Iterable[PrintData.Shape]) = {
     var volume = 1f
-    if (shapes.size > 0) for (x <- 0 until 16 / stepping; y <- 0 until 16 / stepping; z <- 0 until 16 / stepping) {
+    if (shapes.nonEmpty) for (x <- 0 until 16 / stepping; y <- 0 until 16 / stepping; z <- 0 until 16 / stepping) {
       val bounds = AxisAlignedBB.fromBounds(
         x * step, y * step, z * step,
         (x + 1) * step, (y + 1) * step, (z + 1) * step)
diff --git a/src/main/scala/li/cil/oc/common/tileentity/traits/RedstoneAware.scala b/src/main/scala/li/cil/oc/common/tileentity/traits/RedstoneAware.scala
index c5be31e7f..4c40e6740 100644
--- a/src/main/scala/li/cil/oc/common/tileentity/traits/RedstoneAware.scala
+++ b/src/main/scala/li/cil/oc/common/tileentity/traits/RedstoneAware.scala
@@ -38,7 +38,7 @@ trait RedstoneAware extends RotationAware /* with IConnectable with IRedstoneEmi
     if (value != isOutputEnabled) {
       _isOutputEnabled = value
       if (!value) {
-        for (i <- 0 until _output.length) {
+        for (i <- _output.indices) {
           _output(i) = 0
         }
       }
diff --git a/src/main/scala/li/cil/oc/util/ExtendedWorld.scala b/src/main/scala/li/cil/oc/util/ExtendedWorld.scala
index 7ef64766f..4819cb57d 100644
--- a/src/main/scala/li/cil/oc/util/ExtendedWorld.scala
+++ b/src/main/scala/li/cil/oc/util/ExtendedWorld.scala
@@ -43,7 +43,7 @@ object ExtendedWorld {
 
     def getBlockHarvestTool(position: BlockPosition) = getBlock(position).getHarvestTool(getBlockMetadata(position))
 
-    def computeRedstoneSignal(position: BlockPosition, side: EnumFacing) = math.max(world.isBlockProvidingPowerTo(position.offset(side), side.getOpposite), world.getIndirectPowerLevelTo(position.offset(side), side.getOpposite))
+    def computeRedstoneSignal(position: BlockPosition, side: EnumFacing) = math.max(world.isBlockProvidingPowerTo(position.offset(side), side), world.getIndirectPowerLevelTo(position.offset(side), side))
 
     def isBlockProvidingPowerTo(position: BlockPosition, side: EnumFacing) = world.getStrongPower(position.toBlockPos, side)