diff --git a/argus-derive/src/expr/bool_expr.rs b/argus-derive/src/expr/bool_expr.rs
index 3ebed08..478295a 100644
--- a/argus-derive/src/expr/bool_expr.rs
+++ b/argus-derive/src/expr/bool_expr.rs
@@ -39,7 +39,6 @@ fn impl_bool_not(input: &DeriveInput) -> impl ToTokens {
     }
 }
 
-#[derive(Debug, Copy, Clone)]
 enum BoolOp {
     And,
     Or,
diff --git a/argus-derive/src/expr/num_expr.rs b/argus-derive/src/expr/num_expr.rs
index 35c563c..b99b1a5 100644
--- a/argus-derive/src/expr/num_expr.rs
+++ b/argus-derive/src/expr/num_expr.rs
@@ -43,28 +43,27 @@ fn impl_num_neg(input: &DeriveInput) -> impl ToTokens {
     }
 }
 
-#[derive(Debug, Copy, Clone)]
 enum NumOp {
     Add,
     Mul,
 }
 
 impl NumOp {
-    fn get_trait_name(self) -> Ident {
+    fn get_trait_name(&self) -> Ident {
         match self {
             NumOp::Add => Ident::new("Add", Span::call_site()),
             NumOp::Mul => Ident::new("Mul", Span::call_site()),
         }
     }
 
-    fn get_trait_fn(self) -> Ident {
+    fn get_trait_fn(&self) -> Ident {
         match self {
             NumOp::Add => Ident::new("add", Span::call_site()),
             NumOp::Mul => Ident::new("mul", Span::call_site()),
         }
     }
 
-    fn get_expr_name(self) -> Ident {
+    fn get_expr_name(&self) -> Ident {
         match self {
             NumOp::Add => Ident::new("Add", Span::call_site()),
             NumOp::Mul => Ident::new("Mul", Span::call_site()),