diff --git a/src/main/java/club/sk1er/patcher/mixins/performance/forge/InvWrapperMixin_ImproveInsertion.java b/src/main/java/club/sk1er/patcher/mixins/performance/forge/InvWrapperMixin_ImproveInsertion.java
index 09a62e63..7dcc0e1b 100644
--- a/src/main/java/club/sk1er/patcher/mixins/performance/forge/InvWrapperMixin_ImproveInsertion.java
+++ b/src/main/java/club/sk1er/patcher/mixins/performance/forge/InvWrapperMixin_ImproveInsertion.java
@@ -22,7 +22,9 @@ public class InvWrapperMixin_ImproveInsertion {
 
     @Inject(method = "insertItem", at = @At(value = "INVOKE", target = "Lnet/minecraftforge/items/ItemHandlerHelper;canItemStacksStack(Lnet/minecraft/item/ItemStack;Lnet/minecraft/item/ItemStack;)Z"), cancellable = true)
     private void patcher$earlyExit(int slot, ItemStack stack, boolean simulate, CallbackInfoReturnable<ItemStack> cir) {
+        if (this.inv == null) return;
         ItemStack stackInSlot = this.inv.getStackInSlot(slot);
+        if (stackInSlot == null) return;
         if (stackInSlot.stackSize >= Math.min(stackInSlot.getMaxStackSize(), this.inv.getInventoryStackLimit())) {
             cir.setReturnValue(stack);
         }
diff --git a/src/main/java/club/sk1er/patcher/mixins/performance/forge/SidedInvWrapperMixin_ImproveInsertion.java b/src/main/java/club/sk1er/patcher/mixins/performance/forge/SidedInvWrapperMixin_ImproveInsertion.java
index 30635705..a942c14c 100644
--- a/src/main/java/club/sk1er/patcher/mixins/performance/forge/SidedInvWrapperMixin_ImproveInsertion.java
+++ b/src/main/java/club/sk1er/patcher/mixins/performance/forge/SidedInvWrapperMixin_ImproveInsertion.java
@@ -24,7 +24,9 @@ public class SidedInvWrapperMixin_ImproveInsertion {
 
     @Inject(method = "insertItem", at = @At(value = "INVOKE", target = "Lnet/minecraftforge/items/ItemHandlerHelper;canItemStacksStack(Lnet/minecraft/item/ItemStack;Lnet/minecraft/item/ItemStack;)Z", shift = At.Shift.BEFORE), cancellable = true)
     private void patcher$earlyExit(int slot, ItemStack stack, boolean simulate, CallbackInfoReturnable<ItemStack> cir) {
+        if (this.inv == null) return;
         ItemStack stackInSlot = this.inv.getStackInSlot(slot);
+        if (stackInSlot == null) return;
         if (stackInSlot.stackSize >= Math.min(stackInSlot.getMaxStackSize(), this.inv.getInventoryStackLimit())) {
             cir.setReturnValue(stack);
         }