diff --git a/kernel/src/type_checker.rs b/kernel/src/type_checker.rs
index 2b574a8329e57d7011dd7cf5d851381b958cee74..e577d8a426a5921c0eee279fcd04049c5187e083 100644
--- a/kernel/src/type_checker.rs
+++ b/kernel/src/type_checker.rs
@@ -48,11 +48,11 @@ impl<'arena> Arena<'arena> {
     fn conversion(&mut self, lhs: Term<'arena>, rhs: Term<'arena>) -> bool {
         lhs == rhs
             || match (&*self.whnf(lhs), &*self.whnf(rhs)) {
-                (&Prop, &Prop) => true,
+                (Prop, Prop) => true,
 
-                (&Type(ref i), &Type(ref j)) => i == j,
+                (Type(i), Type(j)) => *i == *j,
 
-                (&Var(i, _), &Var(j, _)) => i == j,
+                (Var(i, _), Var(j, _)) => i == j,
 
                 (&Prod(t1, u1), &Prod(t2, u2)) => {
                     self.conversion(t1, t2) && self.conversion(u1, u2)