1 files changed, 17 insertions, 1 deletions

diff --git a/crates/ra_hir_def/src/test_db.rs b/crates/ra_hir_def/src/test_db.rs
index 0756916a8..eb83dee79 100644
--- a/crates/ra_hir_def/src/test_db.rs
+++ b/crates/ra_hir_def/src/test_db.rs
@@ -5,8 +5,12 @@ use std::{
     sync::{Arc, Mutex},
 };
 
+use hir_expand::db::AstDatabase;
+use ra_db::{
+    salsa, CrateId, ExternSourceId, FileId, FileLoader, FileLoaderDelegate, RelativePath, Upcast,
+};
+
 use crate::db::DefDatabase;
-use ra_db::{salsa, CrateId, ExternSourceId, FileId, FileLoader, FileLoaderDelegate, RelativePath};
 
 #[salsa::database(
     ra_db::SourceDatabaseExtStorage,
@@ -21,6 +25,18 @@ pub struct TestDB {
     events: Mutex<Option<Vec<salsa::Event<TestDB>>>>,
 }
 
+impl Upcast<dyn AstDatabase> for TestDB {
+    fn upcast(&self) -> &(dyn AstDatabase + 'static) {
+        &*self
+    }
+}
+
+impl Upcast<dyn DefDatabase> for TestDB {
+    fn upcast(&self) -> &(dyn DefDatabase + 'static) {
+        &*self
+    }
+}
+
 impl salsa::Database for TestDB {
     fn salsa_runtime(&self) -> &salsa::Runtime<Self> {
         &self.runtime