diff --git a/src/pipe.rs b/src/pipe.rs
index 3098fd78bc2..f1d6c4d323e 100644
--- a/src/pipe.rs
+++ b/src/pipe.rs
@@ -45,7 +45,7 @@ mod tests {
     // size.  Bumping the size is not a breaking change but should only be done if really
     // necessary.
 
-    const MAX_SIZE: usize = 2416;
+    const MAX_SIZE: usize = 2432;
 
     fn assert_size<T>() {
         let size = mem::size_of::<T>();
@@ -65,6 +65,7 @@ mod tests {
     #[test]
     fn test_interchange_size() {
         use interchange::Channel;
+        // The real cost per-client
         assert_size::<Channel<Request, Reply>>();
     }
 }