diff --git a/README.md b/README.md
index f2c13e7..ae4428a 100644
--- a/README.md
+++ b/README.md
@@ -104,6 +104,7 @@ let region_live_at: Relation<((Origin, Point), ())> = Vec::new().into();
 // `errors` inferred as the output relation
 let errors = {
     let mut iteration = Iteration::new();
+
     // Intensional predicates, and their indices
 
     let borrow_live_at = iteration.variable::<((Loan, Point), ())>("borrow_live_at");
@@ -134,7 +135,7 @@ let errors = {
     subset.extend(outlives.iter().clone());
 
     // R04: requires(O, L, P) :- borrow_region(O, L, P).
-    requires.extend(borrow_region.iter().map(|&tuple| tuple));
+    requires.extend(borrow_region.iter().clone());
 
     while iteration.changed() {
         // Index maintenance
diff --git a/tests/naive_rules.rs b/tests/naive_rules.rs
index 3acd455..b08b825 100644
--- a/tests/naive_rules.rs
+++ b/tests/naive_rules.rs
@@ -155,6 +155,7 @@ where
     // `errors` inferred as the output relation
     let errors = {
         let mut iteration = Iteration::new();
+
         // Intensional predicates, and their indices
 
         let borrow_live_at = iteration.variable::<((Loan, Point), ())>("borrow_live_at");
@@ -185,7 +186,7 @@ where
         subset.extend(outlives.iter().clone());
 
         // R04: requires(O, L, P) :- borrow_region(O, L, P).
-        requires.extend(borrow_region.iter().map(|&tuple| tuple));
+        requires.extend(borrow_region.iter().clone());
 
         while iteration.changed() {
             // Index maintenance