diff --git a/api/src/cap.rs b/api/src/cap.rs
index 6f078fd..30e2053 100644
--- a/api/src/cap.rs
+++ b/api/src/cap.rs
@@ -1,4 +1,4 @@
-#[derive(Clone, Copy, FromPrimitive, ToPrimitive)]
+#[derive(Clone, Copy, Eq, PartialEq, FromPrimitive, ToPrimitive)]
 pub enum ObjectType {
     Null         = 0,
     CNode        = 1,
diff --git a/kernel/src/objects/null.rs b/kernel/src/objects/null.rs
index c3e2cc6..645b166 100644
--- a/kernel/src/objects/null.rs
+++ b/kernel/src/objects/null.rs
@@ -6,10 +6,13 @@ use core::marker::PhantomData;
 /// NullObject is used as empty (capability) slot
 pub struct NullObject {}
 pub type NullCap<'a> = Cap<'a, NullObject>;
+impl KernelObject for NullObject {
+    const OBJ_TYPE: ObjectType = ObjectType::Null;
+}
 
 impl<'a> NullCap<'a> {
     pub fn mint() -> RawCap {
-        let mut cap = RawCap::new(0, 0, ObjectType::Null);
+        let cap = RawCap::new(0, 0, ObjectType::Null);
         cap
     }