diff --git a/crates/ra_db/src/cancellation.rs b/crates/ra_db/src/cancellation.rs
index f7077b992f4b..32a2685535c5 100644
--- a/crates/ra_db/src/cancellation.rs
+++ b/crates/ra_db/src/cancellation.rs
@@ -29,6 +29,8 @@ impl Canceled {
     }
 
     pub fn throw() -> ! {
+        // We use resume and not panic here to avoid running the panic
+        // hook (that is, to avoid collecting and printing backtrace).
         std::panic::resume_unwind(Box::new(Canceled::new()))
     }
 }