diff --git a/challenger/src/lib.rs b/challenger/src/lib.rs
index 829b3b0..db82fe4 100644
--- a/challenger/src/lib.rs
+++ b/challenger/src/lib.rs
@@ -496,7 +496,7 @@ mod tests {
             let result = reject_challenged_pokes(pokes.clone(), challenges);
             assert_eq!(result.len(), 1);
 
-            let (_, meta) = result.get(0).unwrap();
+            let (_, meta) = result.first().unwrap();
             assert_eq!(meta.block_number, U64::from(3));
         }
 
@@ -552,7 +552,7 @@ mod tests {
             let result = reject_challenged_pokes(pokes.clone(), challenges);
             assert_eq!(result.len(), 2);
 
-            let (_, meta) = result.get(0).unwrap();
+            let (_, meta) = result.first().unwrap();
             assert_eq!(meta.block_number, U64::from(3));
 
             let (_, meta2) = result.get(1).unwrap();