diff --git a/src/vtable.rs b/src/vtable.rs
index 12f7092d935..5788aabaadc 100644
--- a/src/vtable.rs
+++ b/src/vtable.rs
@@ -72,7 +72,10 @@ pub(crate) fn get_vtable<'tcx>(
     let vtable_ptr = if let Some(vtable_ptr) = fx.vtables.get(&(ty, trait_ref)) {
         *vtable_ptr
     } else {
-        let vtable_alloc_id = fx.tcx.vtable_allocation(ty, trait_ref);
+        let vtable_alloc_id = match fx.tcx.vtable_allocation(ty, trait_ref) {
+            Ok(alloc) => alloc,
+            Err(_) => fx.tcx.sess().fatal("allocation of constant vtable failed"),
+        };
         let vtable_allocation = fx.tcx.global_alloc(vtable_alloc_id).unwrap_memory();
         let vtable_ptr = pointer_for_allocation(fx, vtable_allocation);