diff --git a/crates/ra_db/src/lib.rs b/crates/ra_db/src/lib.rs
index c54791b7ae..603daed374 100644
--- a/crates/ra_db/src/lib.rs
+++ b/crates/ra_db/src/lib.rs
@@ -32,11 +32,10 @@ pub trait CheckCanceled {
 
     fn catch_canceled<F, T>(&self, f: F) -> Result<T, Canceled>
     where
-        Self: Sized,
+        Self: Sized + panic::RefUnwindSafe,
         F: FnOnce(&Self) -> T + panic::UnwindSafe,
     {
-        let this = panic::AssertUnwindSafe(self);
-        panic::catch_unwind(|| f(*this)).map_err(|err| match err.downcast::<Canceled>() {
+        panic::catch_unwind(|| f(self)).map_err(|err| match err.downcast::<Canceled>() {
             Ok(canceled) => *canceled,
             Err(payload) => panic::resume_unwind(payload),
         })
diff --git a/crates/ra_hir/src/ty/traits.rs b/crates/ra_hir/src/ty/traits.rs
index d11dab2940..90a11ac7d5 100644
--- a/crates/ra_hir/src/ty/traits.rs
+++ b/crates/ra_hir/src/ty/traits.rs
@@ -30,6 +30,9 @@ impl PartialEq for TraitSolver {
 
 impl Eq for TraitSolver {}
 
+// FIXME: this impl is WRONG, chalk is not RefUnwindSafe, and this causes #1927
+impl std::panic::RefUnwindSafe for TraitSolver {}
+
 impl TraitSolver {
     fn solve(
         &self,