diff --git a/src/main/java/tconstruct/tools/items/ToolPart.java b/src/main/java/tconstruct/tools/items/ToolPart.java
index a10495c6..587b0379 100644
--- a/src/main/java/tconstruct/tools/items/ToolPart.java
+++ b/src/main/java/tconstruct/tools/items/ToolPart.java
@@ -81,8 +81,9 @@ public class ToolPart extends CraftingItem implements IToolPart
     @Override
     public int getMaterialID (ItemStack stack)
     {
-        if(stack.getItemDamage() >= toolMaterialNames.length)
-            return -1;
-        return stack.getItemDamage();
+        if(TConstructRegistry.toolMaterials.keySet().contains(stack.getItemDamage()))
+            return stack.getItemDamage();
+
+        return -1;
     }
 }