diff --git a/src/collections/raw_array.rs b/src/collections/raw_array.rs
index 6773f70e26ca5d08a298111c3a4ef0c8ba3f41cb..9f1e67f7e01065ff611b32b6057443c8f6badd0e 100644
--- a/src/collections/raw_array.rs
+++ b/src/collections/raw_array.rs
@@ -175,7 +175,7 @@ mod tests {
         let mut array = RawArray::new();
         array.resize(max_size);
         fill(&mut array, max_size);
-        for size in sizes {
+        for size in sizes.iter().copied() {
             array.resize(size);
             assert_eq!(array.cap(), size);
         }