diff --git a/crates/hir_def/src/item_tree.rs b/crates/hir_def/src/item_tree.rs
index 6bb334573ef..09bcb10dc0c 100644
--- a/crates/hir_def/src/item_tree.rs
+++ b/crates/hir_def/src/item_tree.rs
@@ -209,18 +209,6 @@ impl ItemTree {
         }
     }
 
-    pub fn source<S: ItemTreeNode>(&self, db: &dyn DefDatabase, of: ItemTreeId<S>) -> S::Source {
-        // This unwrap cannot fail, since it has either succeeded above, or resulted in an empty
-        // ItemTree (in which case there is no valid `FileItemTreeId` to call this method with).
-        let root =
-            db.parse_or_expand(of.file_id).expect("parse_or_expand failed on constructed ItemTree");
-
-        let id = self[of.value].ast_id();
-        let map = db.ast_id_map(of.file_id);
-        let ptr = map.get(id);
-        ptr.to_node(&root)
-    }
-
     fn data(&self) -> &ItemTreeData {
         self.data.as_ref().expect("attempted to access data of empty ItemTree")
     }
diff --git a/crates/hir_ty/src/tests.rs b/crates/hir_ty/src/tests.rs
index fc770ea600c..0a4141e698b 100644
--- a/crates/hir_ty/src/tests.rs
+++ b/crates/hir_ty/src/tests.rs
@@ -19,6 +19,7 @@ use hir_def::{
     item_scope::ItemScope,
     keys,
     nameres::DefMap,
+    src::HasSource,
     AssocItemId, DefWithBodyId, LocalModuleId, Lookup, ModuleDefId,
 };
 use hir_expand::{db::AstDatabase, InFile};
@@ -195,18 +196,15 @@ fn infer_with_mismatches(content: &str, include_mismatches: bool) -> String {
     defs.sort_by_key(|def| match def {
         DefWithBodyId::FunctionId(it) => {
             let loc = it.lookup(&db);
-            let tree = db.item_tree(loc.id.file_id);
-            tree.source(&db, loc.id).syntax().text_range().start()
+            loc.source(&db).value.syntax().text_range().start()
         }
         DefWithBodyId::ConstId(it) => {
             let loc = it.lookup(&db);
-            let tree = db.item_tree(loc.id.file_id);
-            tree.source(&db, loc.id).syntax().text_range().start()
+            loc.source(&db).value.syntax().text_range().start()
         }
         DefWithBodyId::StaticId(it) => {
             let loc = it.lookup(&db);
-            let tree = db.item_tree(loc.id.file_id);
-            tree.source(&db, loc.id).syntax().text_range().start()
+            loc.source(&db).value.syntax().text_range().start()
         }
     });
     for def in defs {