diff --git a/src/runtime.rs b/src/runtime.rs
index a6c2a52d..e032453d 100644
--- a/src/runtime.rs
+++ b/src/runtime.rs
@@ -80,7 +80,7 @@ where
         }
 
         let old_revision = self.shared_state.revision.fetch_add(1, Ordering::SeqCst);
-        assert!(old_revision != usize::max_value());
+        assert!(old_revision != usize::max_value(), "revision overflow");
         let result = Revision {
             generation: 1 + old_revision as u64,
         };