diff --git a/src/libarena/lib.rs b/src/libarena/lib.rs
index c2f4ef3ac30..f212cdd4638 100644
--- a/src/libarena/lib.rs
+++ b/src/libarena/lib.rs
@@ -563,7 +563,7 @@ mod tests {
 
     struct Noncopy {
         string: String,
-        array: Vec<int> ,
+        array: Vec<int>,
     }
 
     #[test]