diff --git a/src/board.rs b/src/board.rs
index 08eaf0d..54727ae 100644
--- a/src/board.rs
+++ b/src/board.rs
@@ -146,8 +146,16 @@ impl Board {
 
         let mut chains: Vec<Vec<(usize, usize)>> = Vec::with_capacity(8);
 
-        chains.extend(i_chain.map(|range| range.map(|i| (i, j)).collect()));
-        chains.extend(j_chain.map(|range| range.map(|j| (i, j)).collect()));
+        chains.extend(
+            i_chain
+                .map(|range| range.map(move |i| (i, j)))
+                .map(Iterator::collect),
+        );
+        chains.extend(
+            j_chain
+                .map(|range| range.map(move |j| (i, j)))
+                .map(Iterator::collect),
+        );
 
         // handle diagonals
         chains.extend(diag(i, j, 0, 0, BOARD_SIZE - 1, BOARD_SIZE - 1).map(Iterator::collect));
diff --git a/src/misc.rs b/src/misc.rs
index 147efff..a379381 100644
--- a/src/misc.rs
+++ b/src/misc.rs
@@ -32,7 +32,7 @@ pub fn diag<T>(
     min_j: T,
     max_i: T,
     max_j: T,
-) -> [impl Iterator<Item = (T, T)>; 4]
+) -> [impl Iterator<Item = (T, T)> + Clone; 4]
 where
     T: num::Integer + Copy,
     RangeInclusive<T>: Iterator<Item = T> + DoubleEndedIterator,
@@ -41,7 +41,7 @@ where
     let i_chains = split_from(min_i, max_i, i);
     let j_chains = split_from(min_j, max_j, j);
 
-    [(0, 0), (1, 1), (1, 0), (0, 1)].map(|(a, b)| i_chains[a].clone().zip(j_chains[b].clone()))
+    [(0, 0), (1, 1), (1, 0), (0, 1)].map(move |(a, b)| i_chains[a].clone().zip(j_chains[b].clone()))
 }
 
 #[cfg(test)]