diff --git a/hugr-core/src/import.rs b/hugr-core/src/import.rs
index db72664e6..ee2237ffa 100644
--- a/hugr-core/src/import.rs
+++ b/hugr-core/src/import.rs
@@ -259,7 +259,7 @@ impl<'a> Context<'a> {
         let name = node_data
             .operation
             .symbol()
-            .ok_or_else(|| model::ModelError::InvalidSymbol(node_id))?;
+            .ok_or(model::ModelError::InvalidSymbol(node_id))?;
         Ok(name)
     }
 
@@ -867,7 +867,7 @@ impl<'a> Context<'a> {
 
                     self.local_vars
                         .get_mut(var)
-                        .ok_or_else(|| model::ModelError::InvalidVar(*var))?
+                        .ok_or(model::ModelError::InvalidVar(*var))?
                         .bound = TypeBound::Copyable;
                 }
                 _ => return Err(error_unsupported!("constraint other than copy or discard")),