diff --git a/tx/src/entities.rs b/tx/src/entities.rs
index 6f741ed0..782a8e1c 100644
--- a/tx/src/entities.rs
+++ b/tx/src/entities.rs
@@ -104,7 +104,7 @@ pub enum EntidOrLookupRefOrTempId {
     TempId(TempId),
 }
 
-#[derive(Clone, Debug, Eq, Hash, Ord, PartialOrd, PartialEq)]
+#[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialOrd, PartialEq)]
 pub enum OpType {
     Add,
     Retract,