diff --git a/src/main/scala/li/cil/oc/integration/opencomputers/DriverAPU.scala b/src/main/scala/li/cil/oc/integration/opencomputers/DriverAPU.scala
index a41112f13..17493abaa 100644
--- a/src/main/scala/li/cil/oc/integration/opencomputers/DriverAPU.scala
+++ b/src/main/scala/li/cil/oc/integration/opencomputers/DriverAPU.scala
@@ -27,7 +27,7 @@ object DriverAPU extends DriverCPU with HostAware with EnvironmentAware {
 
   override def cpuTier(stack: ItemStack) =
     Delegator.subItem(stack) match {
-      case Some(apu: common.item.APU) => apu.tier
+      case Some(apu: common.item.APU) => apu.cpuTier
       case _ => Tier.One
     }
 
diff --git a/src/main/scala/li/cil/oc/integration/opencomputers/DriverCPU.scala b/src/main/scala/li/cil/oc/integration/opencomputers/DriverCPU.scala
index df3cdd997..14db12664 100644
--- a/src/main/scala/li/cil/oc/integration/opencomputers/DriverCPU.scala
+++ b/src/main/scala/li/cil/oc/integration/opencomputers/DriverCPU.scala
@@ -33,7 +33,7 @@ abstract class DriverCPU extends Item with Processor {
 
   def cpuTier(stack: ItemStack): Int =
     Delegator.subItem(stack) match {
-      case Some(cpu: item.CPU) => cpu.tier
+      case Some(cpu: item.CPU) => cpu.cpuTier
       case _ => Tier.One
     }
 
diff --git a/src/main/scala/li/cil/oc/integration/opencomputers/DriverGraphicsCard.scala b/src/main/scala/li/cil/oc/integration/opencomputers/DriverGraphicsCard.scala
index 31b594c1d..b39c4f4d8 100644
--- a/src/main/scala/li/cil/oc/integration/opencomputers/DriverGraphicsCard.scala
+++ b/src/main/scala/li/cil/oc/integration/opencomputers/DriverGraphicsCard.scala
@@ -30,7 +30,7 @@ object DriverGraphicsCard extends Item with HostAware with EnvironmentAware {
 
   override def tier(stack: ItemStack) =
     Delegator.subItem(stack) match {
-      case Some(gpu: common.item.GraphicsCard) => gpu.tier
+      case Some(gpu: common.item.GraphicsCard) => gpu.gpuTier
       case _ => Tier.One
     }