diff --git a/src/main/java/com/raoulvdberge/refinedstorage/inventory/ItemHandlerBasic.java b/src/main/java/com/raoulvdberge/refinedstorage/inventory/ItemHandlerBasic.java
index 44a223025..130b6a484 100755
--- a/src/main/java/com/raoulvdberge/refinedstorage/inventory/ItemHandlerBasic.java
+++ b/src/main/java/com/raoulvdberge/refinedstorage/inventory/ItemHandlerBasic.java
@@ -4,6 +4,8 @@ import net.minecraft.item.ItemStack;
 import net.minecraft.tileentity.TileEntity;
 import net.minecraftforge.items.ItemStackHandler;
 
+import javax.annotation.Nonnull;
+
 public class ItemHandlerBasic extends ItemStackHandler {
     private TileEntity tile;
 
@@ -21,6 +23,7 @@ public class ItemHandlerBasic extends ItemStackHandler {
     }
 
     @Override
+    @Nonnull
     public ItemStack insertItem(int slot, ItemStack stack, boolean simulate) {
         if (validators.length > 0) {
             for (IItemValidator validator : validators) {
@@ -44,6 +47,7 @@ public class ItemHandlerBasic extends ItemStackHandler {
         }
     }
 
+    @Nonnull
     public ItemStack extractItemInternal(int slot, int amount, boolean simulate) {
         return super.extractItem(slot, amount, simulate);
     }
diff --git a/src/main/java/com/raoulvdberge/refinedstorage/tile/TileConstructor.java b/src/main/java/com/raoulvdberge/refinedstorage/tile/TileConstructor.java
index 3fd3d96ea..dbd070973 100755
--- a/src/main/java/com/raoulvdberge/refinedstorage/tile/TileConstructor.java
+++ b/src/main/java/com/raoulvdberge/refinedstorage/tile/TileConstructor.java
@@ -71,7 +71,7 @@ public class TileConstructor extends TileNode implements IComparable, IType {
         protected void onContentsChanged(int slot) {
             super.onContentsChanged(slot);
 
-            item = getStackInSlot(slot) == null ? null : getStackInSlot(slot).copy();
+            item = getStackInSlot(slot).isEmpty() ? null : getStackInSlot(slot).copy();
             block = SlotFilter.getBlockState(getWorld(), pos.offset(getDirection()), getStackInSlot(slot));
         }
     };
diff --git a/src/main/java/com/raoulvdberge/refinedstorage/tile/TileController.java b/src/main/java/com/raoulvdberge/refinedstorage/tile/TileController.java
index 9d8541652..5ead857c6 100755
--- a/src/main/java/com/raoulvdberge/refinedstorage/tile/TileController.java
+++ b/src/main/java/com/raoulvdberge/refinedstorage/tile/TileController.java
@@ -353,14 +353,14 @@ public class TileController extends TileBase implements INetworkMaster, IEnergyR
     }
 
     @Override
-    public void addCraftingTask(ICraftingTask task) {
+    public void addCraftingTask(@Nonnull ICraftingTask task) {
         craftingTasksToAdd.add(task);
 
         markDirty();
     }
 
     @Override
-    public void cancelCraftingTask(ICraftingTask task) {
+    public void cancelCraftingTask(@Nonnull ICraftingTask task) {
         craftingTasksToCancel.add(task);
 
         markDirty();
@@ -580,7 +580,7 @@ public class TileController extends TileBase implements INetworkMaster, IEnergyR
 
     @Override
     public ItemStack insertItem(@Nonnull ItemStack stack, int size, boolean simulate) {
-        if (stack == null || stack.getItem() == null || itemStorage.getStorages().isEmpty()) {
+        if (stack == null || (stack != null && stack.isEmpty()) || itemStorage.getStorages().isEmpty()) {
             return ItemHandlerHelper.copyStackWithSize(stack, size);
         }
 
diff --git a/src/main/java/com/raoulvdberge/refinedstorage/tile/TileCrafter.java b/src/main/java/com/raoulvdberge/refinedstorage/tile/TileCrafter.java
index b6c5fb2a6..24982f0b8 100755
--- a/src/main/java/com/raoulvdberge/refinedstorage/tile/TileCrafter.java
+++ b/src/main/java/com/raoulvdberge/refinedstorage/tile/TileCrafter.java
@@ -81,7 +81,7 @@ public class TileCrafter extends TileNode implements ICraftingPatternContainer {
         for (int i = 0; i < patterns.getSlots(); ++i) {
             ItemStack patternStack = patterns.getStackInSlot(i);
 
-            if (patternStack != null) {
+            if (!patternStack.isEmpty()) {
                 ICraftingPattern pattern = ((ICraftingPatternProvider) patternStack.getItem()).create(getWorld(), patternStack, this);
 
                 if (pattern.isValid()) {
@@ -96,7 +96,7 @@ public class TileCrafter extends TileNode implements ICraftingPatternContainer {
         int usage = RS.INSTANCE.config.crafterUsage + upgrades.getEnergyUsage();
 
         for (int i = 0; i < patterns.getSlots(); ++i) {
-            if (patterns.getStackInSlot(i) != null) {
+            if (!patterns.getStackInSlot(i).isEmpty()) {
                 usage += RS.INSTANCE.config.crafterPerPatternUsage;
             }
         }
diff --git a/src/main/java/com/raoulvdberge/refinedstorage/tile/TileDestructor.java b/src/main/java/com/raoulvdberge/refinedstorage/tile/TileDestructor.java
index d42c08d1a..9cdc42adb 100755
--- a/src/main/java/com/raoulvdberge/refinedstorage/tile/TileDestructor.java
+++ b/src/main/java/com/raoulvdberge/refinedstorage/tile/TileDestructor.java
@@ -94,7 +94,6 @@ public class TileDestructor extends TileNode implements IComparable, IFilterable
     @Override
     public void updateNode() {
         if (ticks % upgrades.getSpeed(BASE_SPEED, 4) == 0) {
-
             BlockPos front = pos.offset(getDirection());
 
             if (pickupItem && type == IType.ITEMS) {
@@ -123,7 +122,7 @@ public class TileDestructor extends TileNode implements IComparable, IFilterable
                 @SuppressWarnings("deprecation")
                 ItemStack frontStack = frontBlock.getItem(getWorld(), front, frontBlockState);
 
-                if (frontStack != null) {
+                if (!frontStack.isEmpty()) {
                     if (IFilterable.canTake(itemFilters, mode, compare, frontStack) && frontBlockState.getBlockHardness(getWorld(), front) != -1.0) {
                         List<ItemStack> drops;
                         if (upgrades.hasUpgrade(ItemUpgrade.TYPE_SILK_TOUCH) && frontBlock.canSilkHarvest(getWorld(), front, frontBlockState, null)) {
diff --git a/src/main/java/com/raoulvdberge/refinedstorage/tile/TileDetector.java b/src/main/java/com/raoulvdberge/refinedstorage/tile/TileDetector.java
index d93dff8e6..dd0ecbce1 100755
--- a/src/main/java/com/raoulvdberge/refinedstorage/tile/TileDetector.java
+++ b/src/main/java/com/raoulvdberge/refinedstorage/tile/TileDetector.java
@@ -110,7 +110,7 @@ public class TileDetector extends TileNode implements IComparable, IType {
             if (type == IType.ITEMS) {
                 ItemStack slot = itemFilters.getStackInSlot(0);
 
-                if (slot != null) {
+                if (!slot.isEmpty()) {
                     if (mode == MODE_AUTOCRAFTING) {
                         boolean found = false;
 
diff --git a/src/main/java/com/raoulvdberge/refinedstorage/tile/TileDiskDrive.java b/src/main/java/com/raoulvdberge/refinedstorage/tile/TileDiskDrive.java
index e8fc667ff..21978011c 100755
--- a/src/main/java/com/raoulvdberge/refinedstorage/tile/TileDiskDrive.java
+++ b/src/main/java/com/raoulvdberge/refinedstorage/tile/TileDiskDrive.java
@@ -213,7 +213,7 @@ public class TileDiskDrive extends TileNode implements IItemStorageProvider, IFl
         int usage = RS.INSTANCE.config.diskDriveUsage;
 
         for (int i = 0; i < disks.getSlots(); ++i) {
-            if (disks.getStackInSlot(i) != null) {
+            if (!disks.getStackInSlot(i).isEmpty()) {
                 usage += RS.INSTANCE.config.diskDrivePerDiskUsage;
             }
         }
@@ -507,7 +507,7 @@ public class TileDiskDrive extends TileNode implements IItemStorageProvider, IFl
         for (int i = 0; i < disks.getSlots(); ++i) {
             ItemStack disk = disks.getStackInSlot(i);
 
-            if (disk != null) {
+            if (!disk.isEmpty()) {
                 stored += disk.getItem() == RSItems.STORAGE_DISK ? ItemStorageNBT.getStoredFromNBT(disk.getTagCompound()) : FluidStorageNBT.getStoredFromNBT(disk.getTagCompound());
             }
         }
@@ -522,7 +522,7 @@ public class TileDiskDrive extends TileNode implements IItemStorageProvider, IFl
         for (int i = 0; i < disks.getSlots(); ++i) {
             ItemStack disk = disks.getStackInSlot(i);
 
-            if (disk != null) {
+            if (!disk.isEmpty()) {
                 int diskCapacity = disk.getItem() == RSItems.STORAGE_DISK ? EnumItemStorageType.getById(disk.getItemDamage()).getCapacity() : EnumFluidStorageType.getById(disk.getItemDamage()).getCapacity();
 
                 if (diskCapacity == -1) {
diff --git a/src/main/java/com/raoulvdberge/refinedstorage/tile/TileDiskManipulator.java b/src/main/java/com/raoulvdberge/refinedstorage/tile/TileDiskManipulator.java
index 95f486939..beea949ed 100755
--- a/src/main/java/com/raoulvdberge/refinedstorage/tile/TileDiskManipulator.java
+++ b/src/main/java/com/raoulvdberge/refinedstorage/tile/TileDiskManipulator.java
@@ -31,6 +31,7 @@ import net.minecraftforge.items.IItemHandler;
 import net.minecraftforge.items.ItemHandlerHelper;
 import net.minecraftforge.items.wrapper.CombinedInvWrapper;
 
+import javax.annotation.Nonnull;
 import java.util.ArrayList;
 
 public class TileDiskManipulator extends TileNode implements IComparable, IFilterable, IType {
@@ -84,6 +85,7 @@ public class TileDiskManipulator extends TileNode implements IComparable, IFilte
         }
 
         @Override
+        @Nonnull
         public ItemStack extractItem(int slot, int amount, boolean simulate) {
             if (itemStorages[slot] != null) {
                 itemStorages[slot].writeToNBT();
@@ -427,9 +429,9 @@ public class TileDiskManipulator extends TileNode implements IComparable, IFilte
 
     private void moveDriveToOutput(int slot) {
         ItemStack disk = inputDisks.getStackInSlot(slot);
-        if (disk != null) {
+        if (!disk.isEmpty()) {
             int i = 0;
-            while (i < 3 && outputDisks.getStackInSlot(i) != null) {
+            while (i < 3 && !outputDisks.getStackInSlot(i).isEmpty()) {
                 i++;
             }
 
diff --git a/src/main/java/com/raoulvdberge/refinedstorage/tile/TileExporter.java b/src/main/java/com/raoulvdberge/refinedstorage/tile/TileExporter.java
index 22b585606..2d7d817a2 100755
--- a/src/main/java/com/raoulvdberge/refinedstorage/tile/TileExporter.java
+++ b/src/main/java/com/raoulvdberge/refinedstorage/tile/TileExporter.java
@@ -56,14 +56,14 @@ public class TileExporter extends TileNode implements IComparable, IType {
                     for (int i = 0; i < itemFilters.getSlots(); ++i) {
                         ItemStack slot = itemFilters.getStackInSlot(i);
 
-                        if (slot != null) {
+                        if (!slot.isEmpty()) {
                             ItemStack took = network.extractItem(slot, upgrades.getItemInteractCount(), compare, true);
 
                             if (took == null) {
                                 if (upgrades.hasUpgrade(ItemUpgrade.TYPE_CRAFTING)) {
                                     network.scheduleCraftingTask(slot, 1, compare);
                                 }
-                            } else if (ItemHandlerHelper.insertItem(handler, took, true) == null) {
+                            } else if (ItemHandlerHelper.insertItem(handler, took, true).isEmpty()) {
                                 took = network.extractItem(slot, upgrades.getItemInteractCount(), compare, false);
 
                                 ItemHandlerHelper.insertItem(handler, took, false);
diff --git a/src/main/java/com/raoulvdberge/refinedstorage/tile/TileFluidInterface.java b/src/main/java/com/raoulvdberge/refinedstorage/tile/TileFluidInterface.java
index b31fbaf87..7e1aab164 100755
--- a/src/main/java/com/raoulvdberge/refinedstorage/tile/TileFluidInterface.java
+++ b/src/main/java/com/raoulvdberge/refinedstorage/tile/TileFluidInterface.java
@@ -92,7 +92,7 @@ public class TileFluidInterface extends TileNode implements IComparable {
     public void updateNode() {
         ItemStack container = in.getStackInSlot(0);
 
-        if (container != null) {
+        if (!container.isEmpty()) {
             FluidStack fluid = RSUtils.getFluidFromStack(container, true);
 
             if (fluid != null && tankIn.fillInternal(fluid, false) == fluid.amount) {
diff --git a/src/main/java/com/raoulvdberge/refinedstorage/tile/TileImporter.java b/src/main/java/com/raoulvdberge/refinedstorage/tile/TileImporter.java
index dca96f740..e78eb85d1 100755
--- a/src/main/java/com/raoulvdberge/refinedstorage/tile/TileImporter.java
+++ b/src/main/java/com/raoulvdberge/refinedstorage/tile/TileImporter.java
@@ -68,12 +68,12 @@ public class TileImporter extends TileNode implements IComparable, IFilterable,
             if (handler.getSlots() > 0) {
                 ItemStack stack = handler.getStackInSlot(currentSlot);
 
-                if (stack == null || !IFilterable.canTake(itemFilters, mode, compare, stack)) {
+                if (stack.isEmpty() || !IFilterable.canTake(itemFilters, mode, compare, stack)) {
                     currentSlot++;
                 } else if (ticks % upgrades.getSpeed() == 0) {
                     ItemStack result = handler.extractItem(currentSlot, upgrades.getItemInteractCount(), true);
 
-                    if (result != null && network.insertItem(result, result.getCount(), true) == null) {
+                    if (!result.isEmpty() && network.insertItem(result, result.getCount(), true) == null) {
                         network.insertItem(result, result.getCount(), false);
 
                         handler.extractItem(currentSlot, upgrades.getItemInteractCount(), false);
diff --git a/src/main/java/com/raoulvdberge/refinedstorage/tile/TileInterface.java b/src/main/java/com/raoulvdberge/refinedstorage/tile/TileInterface.java
index 409e8e798..5de107ba9 100755
--- a/src/main/java/com/raoulvdberge/refinedstorage/tile/TileInterface.java
+++ b/src/main/java/com/raoulvdberge/refinedstorage/tile/TileInterface.java
@@ -16,6 +16,8 @@ import net.minecraftforge.items.CapabilityItemHandler;
 import net.minecraftforge.items.IItemHandler;
 import net.minecraftforge.items.wrapper.CombinedInvWrapper;
 
+import javax.annotation.Nonnull;
+
 public class TileInterface extends TileNode implements IComparable {
     public static final TileDataParameter<Integer> COMPARE = IComparable.createParameter();
 
@@ -26,6 +28,7 @@ public class TileInterface extends TileNode implements IComparable {
     private ItemHandlerBasic exportSpecimenItems = new ItemHandlerBasic(9, this);
     private ItemHandlerBasic exportItems = new ItemHandlerBasic(9, this) {
         @Override
+        @Nonnull
         public ItemStack insertItem(int slot, ItemStack stack, boolean simulate) {
             return stack;
         }
@@ -54,7 +57,7 @@ public class TileInterface extends TileNode implements IComparable {
 
         ItemStack slot = importItems.getStackInSlot(currentSlot);
 
-        if (slot == null) {
+        if (slot.isEmpty()) {
             currentSlot++;
         } else if (ticks % upgrades.getSpeed() == 0) {
             int size = Math.min(slot.getCount(), upgrades.getItemInteractCount());
@@ -65,6 +68,7 @@ public class TileInterface extends TileNode implements IComparable {
                 importItems.extractItemInternal(currentSlot, size, false);
             } else {
                 importItems.extractItemInternal(currentSlot, size - remainder.getCount(), false);
+
                 currentSlot++;
             }
         }
@@ -73,18 +77,18 @@ public class TileInterface extends TileNode implements IComparable {
             ItemStack wanted = exportSpecimenItems.getStackInSlot(i);
             ItemStack got = exportItems.getStackInSlot(i);
 
-            if (wanted == null) {
-                if (got != null) {
-                    exportItems.setStackInSlot(i, network.insertItem(got, got.getCount(), false));
+            if (wanted.isEmpty()) {
+                if (!got.isEmpty()) {
+                    exportItems.setStackInSlot(i, RSUtils.getStack(network.insertItem(got, got.getCount(), false)));
                 }
             } else {
-                int delta = got == null ? wanted.getCount() : (wanted.getCount() - got.getCount());
+                int delta = got.isEmpty() ? wanted.getCount() : (wanted.getCount() - got.getCount());
 
                 if (delta > 0) {
                     ItemStack result = network.extractItem(wanted, delta, compare, false);
 
                     if (result != null) {
-                        if (exportItems.getStackInSlot(i) == null) {
+                        if (exportItems.getStackInSlot(i).isEmpty()) {
                             exportItems.setStackInSlot(i, result);
                         } else {
                             exportItems.getStackInSlot(i).grow(result.getCount());
diff --git a/src/main/java/com/raoulvdberge/refinedstorage/tile/TileNetworkTransmitter.java b/src/main/java/com/raoulvdberge/refinedstorage/tile/TileNetworkTransmitter.java
index 5ef7f4e36..47269decc 100755
--- a/src/main/java/com/raoulvdberge/refinedstorage/tile/TileNetworkTransmitter.java
+++ b/src/main/java/com/raoulvdberge/refinedstorage/tile/TileNetworkTransmitter.java
@@ -57,7 +57,7 @@ public class TileNetworkTransmitter extends TileNode {
 
             ItemStack card = getStackInSlot(slot);
 
-            if (card == null) {
+            if (card.isEmpty()) {
                 receiver = null;
             } else {
                 receiver = ItemNetworkCard.getReceiver(card);
diff --git a/src/main/java/com/raoulvdberge/refinedstorage/tile/TileProcessingPatternEncoder.java b/src/main/java/com/raoulvdberge/refinedstorage/tile/TileProcessingPatternEncoder.java
index 62fc0d812..2830f2adf 100755
--- a/src/main/java/com/raoulvdberge/refinedstorage/tile/TileProcessingPatternEncoder.java
+++ b/src/main/java/com/raoulvdberge/refinedstorage/tile/TileProcessingPatternEncoder.java
@@ -79,7 +79,7 @@ public class TileProcessingPatternEncoder extends TileBase {
             ItemPattern.setOredict(pattern, oredictPattern);
 
             for (int i = 0; i < 18; ++i) {
-                if (configuration.getStackInSlot(i) != null) {
+                if (!configuration.getStackInSlot(i).isEmpty()) {
                     if (i >= 9) {
                         ItemPattern.addOutput(pattern, configuration.getStackInSlot(i));
                     } else {
@@ -97,18 +97,18 @@ public class TileProcessingPatternEncoder extends TileBase {
         int inputsFilled = 0, outputsFilled = 0;
 
         for (int i = 0; i < 9; ++i) {
-            if (configuration.getStackInSlot(i) != null) {
+            if (!configuration.getStackInSlot(i).isEmpty()) {
                 inputsFilled++;
             }
         }
 
         for (int i = 9; i < 18; ++i) {
-            if (configuration.getStackInSlot(i) != null) {
+            if (!configuration.getStackInSlot(i).isEmpty()) {
                 outputsFilled++;
             }
         }
 
-        return inputsFilled > 0 && outputsFilled > 0 && patterns.getStackInSlot(0) != null && patterns.getStackInSlot(1) == null;
+        return inputsFilled > 0 && outputsFilled > 0 && !patterns.getStackInSlot(0).isEmpty() && patterns.getStackInSlot(1).isEmpty();
     }
 
     public ItemHandlerBasic getPatterns() {
diff --git a/src/main/java/com/raoulvdberge/refinedstorage/tile/TileSolderer.java b/src/main/java/com/raoulvdberge/refinedstorage/tile/TileSolderer.java
index e2600fa4d..ccc6ed1ab 100755
--- a/src/main/java/com/raoulvdberge/refinedstorage/tile/TileSolderer.java
+++ b/src/main/java/com/raoulvdberge/refinedstorage/tile/TileSolderer.java
@@ -19,6 +19,8 @@ import net.minecraftforge.items.CapabilityItemHandler;
 import net.minecraftforge.items.IItemHandler;
 import net.minecraftforge.items.wrapper.CombinedInvWrapper;
 
+import javax.annotation.Nonnull;
+
 public class TileSolderer extends TileNode {
     public static final TileDataParameter<Integer> DURATION = new TileDataParameter<>(DataSerializers.VARINT, 0, new ITileDataProducer<Integer, TileSolderer>() {
         @Override
@@ -46,6 +48,7 @@ public class TileSolderer extends TileNode {
 
     private ItemHandlerBasic items = new ItemHandlerBasic(3, this) {
         @Override
+        @Nonnull
         public ItemStack insertItem(int slot, ItemStack stack, boolean simulate) {
             for (ISoldererRecipe recipe : API.instance().getSoldererRegistry().getRecipes()) {
                 if (API.instance().getComparer().isEqualNoQuantity(recipe.getRow(slot), stack) || API.instance().getComparer().isEqualOredict(recipe.getRow(slot), stack)) {
@@ -58,6 +61,7 @@ public class TileSolderer extends TileNode {
     };
     private ItemHandlerBasic result = new ItemHandlerBasic(1, this) {
         @Override
+        @Nonnull
         public ItemStack insertItem(int slot, ItemStack stack, boolean simulate) {
             return stack;
         }
@@ -82,7 +86,7 @@ public class TileSolderer extends TileNode {
 
     @Override
     public void updateNode() {
-        if (items.getStackInSlot(1) == null && items.getStackInSlot(2) == null && result.getStackInSlot(0) == null) {
+        if (items.getStackInSlot(1).isEmpty() && items.getStackInSlot(2).isEmpty() && result.getStackInSlot(0).isEmpty()) {
             stop();
         } else {
             ISoldererRecipe newRecipe = API.instance().getSoldererRegistry().getRecipe(items);
@@ -90,9 +94,9 @@ public class TileSolderer extends TileNode {
             if (newRecipe == null) {
                 stop();
             } else if (newRecipe != recipe) {
-                boolean sameItem = result.getStackInSlot(0) != null && API.instance().getComparer().isEqualNoQuantity(result.getStackInSlot(0), newRecipe.getResult());
+                boolean sameItem = !result.getStackInSlot(0).isEmpty() && API.instance().getComparer().isEqualNoQuantity(result.getStackInSlot(0), newRecipe.getResult());
 
-                if (result.getStackInSlot(0) == null || (sameItem && ((result.getStackInSlot(0).getCount() + newRecipe.getResult().getCount()) <= result.getStackInSlot(0).getMaxStackSize()))) {
+                if (result.getStackInSlot(0).isEmpty() || (sameItem && ((result.getStackInSlot(0).getCount() + newRecipe.getResult().getCount()) <= result.getStackInSlot(0).getMaxStackSize()))) {
                     recipe = newRecipe;
                     progress = 0;
                     working = true;
@@ -103,7 +107,7 @@ public class TileSolderer extends TileNode {
                 progress += 1 + upgrades.getUpgradeCount(ItemUpgrade.TYPE_SPEED);
 
                 if (progress >= recipe.getDuration()) {
-                    if (result.getStackInSlot(0) != null) {
+                    if (!result.getStackInSlot(0).isEmpty()) {
                         result.getStackInSlot(0).grow(recipe.getResult().getCount());
                     } else {
                         result.setStackInSlot(0, recipe.getResult().copy());
diff --git a/src/main/java/com/raoulvdberge/refinedstorage/tile/externalstorage/ItemStorageDrawer.java b/src/main/java/com/raoulvdberge/refinedstorage/tile/externalstorage/ItemStorageDrawer.java
index ddd123b7f..65897071a 100755
--- a/src/main/java/com/raoulvdberge/refinedstorage/tile/externalstorage/ItemStorageDrawer.java
+++ b/src/main/java/com/raoulvdberge/refinedstorage/tile/externalstorage/ItemStorageDrawer.java
@@ -63,10 +63,6 @@ public class ItemStorageDrawer extends ItemStorageExternal {
         return Collections.emptyList();
     }
 
-    public static boolean isVoidable(IDrawer drawer) {
-        return drawer instanceof IVoidable & ((IVoidable) drawer).isVoid();
-    }
-
     public static ItemStack insertItem(TileExternalStorage externalStorage, IDrawer drawer, ItemStack stack, int size, boolean simulate) {
         if (IFilterable.canTake(externalStorage.getItemFilters(), externalStorage.getMode(), externalStorage.getCompare(), stack) && drawer.canItemBeStored(stack)) {
             int stored = drawer.getStoredItemCount();
@@ -88,7 +84,7 @@ public class ItemStorageDrawer extends ItemStorageExternal {
 
             int returnSize = size - inserted;
 
-            if (isVoidable(drawer)) {
+            if (drawer instanceof IVoidable && ((IVoidable) drawer).isVoid()) {
                 returnSize = -returnSize;
             }
 
diff --git a/src/main/java/com/raoulvdberge/refinedstorage/tile/externalstorage/ItemStorageExternal.java b/src/main/java/com/raoulvdberge/refinedstorage/tile/externalstorage/ItemStorageExternal.java
index 82df2d231..6c2bcedd9 100755
--- a/src/main/java/com/raoulvdberge/refinedstorage/tile/externalstorage/ItemStorageExternal.java
+++ b/src/main/java/com/raoulvdberge/refinedstorage/tile/externalstorage/ItemStorageExternal.java
@@ -41,14 +41,14 @@ public abstract class ItemStorageExternal implements IItemStorage {
 
             ItemStack cached = cache.get(i);
 
-            if (cached != null && actual == null) {
-                // If the cached is not null but the actual is, we remove this item
+            if (cached != ItemStack.EMPTY && actual == ItemStack.EMPTY) {
+                // If the cached is not empty but the actual is, we remove this item
                 network.getItemStorageCache().remove(cached, cached.getCount());
-            } else if (cached == null && actual != null) {
-                // If the cached is null and the actual isn't, we added this item
+            } else if (cached == ItemStack.EMPTY && actual != ItemStack.EMPTY) {
+                // If the cached is empty and the actual isn't, we added this item
                 network.getItemStorageCache().add(actual, actual.getCount(), false);
-            } else if (cached == null && actual == null) {
-                // If they're both null, nothing happens
+            } else if (cached == ItemStack.EMPTY && actual == ItemStack.EMPTY) {
+                // If they're both empty, nothing happens
             } else if (!API.instance().getComparer().isEqualNoQuantity(cached, actual)) {
                 // If both items mismatch, remove the old and add the new
                 network.getItemStorageCache().remove(cached, cached.getCount());
@@ -68,7 +68,7 @@ public abstract class ItemStorageExternal implements IItemStorage {
         // In that case, we remove the items that have been removed due to the shrinkage
         if (cache.size() > newStacks.size()) {
             for (int i = newStacks.size(); i < cache.size(); ++i) {
-                if (cache.get(i) != null) {
+                if (cache.get(i) != ItemStack.EMPTY) {
                     network.getItemStorageCache().remove(cache.get(i), cache.get(i).getCount());
                 }
             }
diff --git a/src/main/java/com/raoulvdberge/refinedstorage/tile/externalstorage/ItemStorageItemHandler.java b/src/main/java/com/raoulvdberge/refinedstorage/tile/externalstorage/ItemStorageItemHandler.java
index ec503437b..2d8dd5491 100755
--- a/src/main/java/com/raoulvdberge/refinedstorage/tile/externalstorage/ItemStorageItemHandler.java
+++ b/src/main/java/com/raoulvdberge/refinedstorage/tile/externalstorage/ItemStorageItemHandler.java
@@ -7,6 +7,7 @@ import net.minecraft.item.ItemStack;
 import net.minecraftforge.items.IItemHandler;
 import net.minecraftforge.items.ItemHandlerHelper;
 
+import javax.annotation.Nonnull;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -34,14 +35,14 @@ public class ItemStorageItemHandler extends ItemStorageExternal {
         List<ItemStack> items = new ArrayList<>();
 
         for (int i = 0; i < handler.getSlots(); ++i) {
-            items.add(handler.getStackInSlot(i) != null ? handler.getStackInSlot(i).copy() : null);
+            items.add(!handler.getStackInSlot(i).isEmpty() ? handler.getStackInSlot(i).copy() : null);
         }
 
         return items;
     }
 
     @Override
-    public ItemStack insertItem(ItemStack stack, int size, boolean simulate) {
+    public ItemStack insertItem(@Nonnull ItemStack stack, int size, boolean simulate) {
         if (IFilterable.canTake(externalStorage.getItemFilters(), externalStorage.getMode(), externalStorage.getCompare(), stack)) {
             return ItemHandlerHelper.insertItem(handler, ItemHandlerHelper.copyStackWithSize(stack, size), simulate);
         }
@@ -50,7 +51,7 @@ public class ItemStorageItemHandler extends ItemStorageExternal {
     }
 
     @Override
-    public ItemStack extractItem(ItemStack stack, int size, int flags, boolean simulate) {
+    public ItemStack extractItem(@Nonnull ItemStack stack, int size, int flags, boolean simulate) {
         int remaining = size;
 
         ItemStack received = null;
@@ -58,10 +59,10 @@ public class ItemStorageItemHandler extends ItemStorageExternal {
         for (int i = 0; i < handler.getSlots(); ++i) {
             ItemStack slot = handler.getStackInSlot(i);
 
-            if (slot != null && API.instance().getComparer().isEqual(slot, stack, flags)) {
+            if (!slot.isEmpty() && API.instance().getComparer().isEqual(slot, stack, flags)) {
                 ItemStack got = handler.extractItem(i, remaining, simulate);
 
-                if (got != null) {
+                if (!got.isEmpty()) {
                     if (received == null) {
                         received = got;
                     } else {
@@ -85,7 +86,7 @@ public class ItemStorageItemHandler extends ItemStorageExternal {
         int size = 0;
 
         for (int i = 0; i < handler.getSlots(); ++i) {
-            if (handler.getStackInSlot(i) != null) {
+            if (!handler.getStackInSlot(i).isEmpty()) {
                 size += handler.getStackInSlot(i).getCount();
             }
         }
diff --git a/src/main/java/com/raoulvdberge/refinedstorage/tile/grid/TileGrid.java b/src/main/java/com/raoulvdberge/refinedstorage/tile/grid/TileGrid.java
index 09b2b74fb..7d4cea73b 100755
--- a/src/main/java/com/raoulvdberge/refinedstorage/tile/grid/TileGrid.java
+++ b/src/main/java/com/raoulvdberge/refinedstorage/tile/grid/TileGrid.java
@@ -276,7 +276,7 @@ public class TileGrid extends TileNode implements IGrid {
 
             if (i < remainder.size() && !remainder.get(i).isEmpty()) {
                 // If there is no space for the remainder, dump it in the player inventory
-                if (slot != null && slot.getCount() > 1) {
+                if (!slot.isEmpty() && slot.getCount() > 1) {
                     if (!player.inventory.addItemStackToInventory(remainder.get(i).copy())) {
                         ItemStack remainderStack = network.insertItem(remainder.get(i).copy(), remainder.get(i).getCount(), false);
 
@@ -289,7 +289,7 @@ public class TileGrid extends TileNode implements IGrid {
                 } else {
                     matrix.setInventorySlotContents(i, remainder.get(i).copy());
                 }
-            } else if (slot != null) {
+            } else if (!slot.isEmpty()) {
                 if (slot.getCount() == 1 && isConnected()) {
                     matrix.setInventorySlotContents(i, network.extractItem(slot, 1, false));
                 } else {
@@ -342,7 +342,7 @@ public class TileGrid extends TileNode implements IGrid {
             for (int i = 0; i < 9; ++i) {
                 ItemStack ingredient = matrix.getStackInSlot(i);
 
-                if (ingredient != null) {
+                if (!ingredient.isEmpty()) {
                     ItemPattern.setSlot(pattern, i, ingredient);
                 }
             }
@@ -352,7 +352,7 @@ public class TileGrid extends TileNode implements IGrid {
     }
 
     public boolean canCreatePattern() {
-        return result.getStackInSlot(0) != null && patterns.getStackInSlot(1) == null && patterns.getStackInSlot(0) != null;
+        return !result.getStackInSlot(0).isEmpty() && patterns.getStackInSlot(1).isEmpty() && patterns.getStackInSlot(0) != null;
     }
 
     public void onRecipeTransfer(EntityPlayer player, ItemStack[][] recipe) {
@@ -360,7 +360,7 @@ public class TileGrid extends TileNode implements IGrid {
         for (int i = 0; i < matrix.getSizeInventory(); ++i) {
             ItemStack slot = matrix.getStackInSlot(i);
 
-            if (slot != null) {
+            if (!slot.isEmpty()) {
                 // Only if we are a crafting grid. Pattern grids can just be emptied.
                 if (getType() == EnumGridType.CRAFTING) {
                     // If we are connected, try to insert into network. If it fails, stop.
@@ -378,7 +378,7 @@ public class TileGrid extends TileNode implements IGrid {
                     }
                 }
 
-                matrix.setInventorySlotContents(i, null);
+                matrix.setInventorySlotContents(i, ItemStack.EMPTY);
             }
         }
 
@@ -397,7 +397,7 @@ public class TileGrid extends TileNode implements IGrid {
                             ItemStack took = network.extractItem(possibility, 1, false);
 
                             if (took != null) {
-                                matrix.setInventorySlotContents(i, took);
+                                matrix.setInventorySlotContents(i, RSUtils.getStack(took));
 
                                 found = true;