diff --git a/crates/ra_hir_def/src/body.rs b/crates/ra_hir_def/src/body.rs
index 9c5272c2d9c..4f2350915dc 100644
--- a/crates/ra_hir_def/src/body.rs
+++ b/crates/ra_hir_def/src/body.rs
@@ -243,7 +243,7 @@ impl Body {
             }
         };
         let expander = Expander::new(db, file_id, module);
-        let (body, source_map) = Body::new(db, file_id, def, expander, params, body);
+        let (body, source_map) = Body::new(db, def, expander, params, body);
         (Arc::new(body), Arc::new(source_map))
     }
 
@@ -253,13 +253,12 @@ impl Body {
 
     fn new(
         db: &dyn DefDatabase,
-        file_id: HirFileId,
         def: DefWithBodyId,
         expander: Expander,
         params: Option<ast::ParamList>,
         body: Option<ast::Expr>,
     ) -> (Body, BodySourceMap) {
-        lower::lower(db, file_id, def, expander, params, body)
+        lower::lower(db, def, expander, params, body)
     }
 }
 
diff --git a/crates/ra_hir_def/src/body/lower.rs b/crates/ra_hir_def/src/body/lower.rs
index a74136b8e6b..852d5cda772 100644
--- a/crates/ra_hir_def/src/body/lower.rs
+++ b/crates/ra_hir_def/src/body/lower.rs
@@ -57,17 +57,15 @@ impl LowerCtx {
 
 pub(super) fn lower(
     db: &dyn DefDatabase,
-    file_id: HirFileId,
     def: DefWithBodyId,
     expander: Expander,
     params: Option<ast::ParamList>,
     body: Option<ast::Expr>,
 ) -> (Body, BodySourceMap) {
-    let item_tree = db.item_tree(file_id);
+    let item_tree = db.item_tree(expander.current_file_id);
     ExprCollector {
         db,
         def,
-        expander,
         source_map: BodySourceMap::default(),
         body: Body {
             exprs: Arena::default(),
@@ -76,7 +74,8 @@ pub(super) fn lower(
             body_expr: dummy_expr_id(),
             item_scope: Default::default(),
         },
-        item_trees: vec![(file_id, item_tree)],
+        item_trees: vec![(expander.current_file_id, item_tree)],
+        expander,
     }
     .collect(params, body)
 }