diff --git a/src/collections/scoped_buffer.rs b/src/collections/scoped_buffer.rs
index da789984728f3c4796ea46d3715fc91395ab10fd..956d77b87b9fd6351d77e29b7bf54454b59683c0 100644
--- a/src/collections/scoped_buffer.rs
+++ b/src/collections/scoped_buffer.rs
@@ -176,7 +176,10 @@ impl<T> std::ops::IndexMut<usize> for ScopedSection<T> {
     }
 }
 
-#[cfg(debug_assertions)]
+// note: this `Drop` impl used to be debug-only, requiring the programmer to
+// call `into_vec` or `forget`. But this is rather error prone. So we'll check
+// in debug mode, but always truncate in release mode (even though this is a
+// noop in most cases).
 impl<T: Sized> Drop for ScopedSection<T> {
     fn drop(&mut self) {
         let vec = unsafe{&mut *self.inner};