diff --git a/src/librustc/dep_graph/dep_node.rs b/src/librustc/dep_graph/dep_node.rs
index 7c21bba49f81b..f7af869fee66b 100644
--- a/src/librustc/dep_graph/dep_node.rs
+++ b/src/librustc/dep_graph/dep_node.rs
@@ -645,6 +645,18 @@ impl<'a, 'gcx: 'tcx + 'a, 'tcx: 'a> DepNodeParams<'a, 'gcx, 'tcx> for (DefIndex,
     }
 }
 
+impl<'a, 'gcx: 'tcx + 'a, 'tcx: 'a> DepNodeParams<'a, 'gcx, 'tcx> for (DefIndex,) {
+    const CAN_RECONSTRUCT_QUERY_KEY: bool = true;
+
+    fn to_fingerprint(&self, tcx: TyCtxt) -> Fingerprint {
+        tcx.hir.definitions().def_path_hash(self.0).0
+    }
+
+    fn to_debug_str(&self, _tcx: TyCtxt<'a, 'gcx, 'tcx>) -> String {
+        format!("{:?}", *self)
+    }
+}
+
 impl<'a, 'gcx: 'tcx + 'a, 'tcx: 'a> DepNodeParams<'a, 'gcx, 'tcx> for (DefId, DefId) {
     const CAN_RECONSTRUCT_QUERY_KEY: bool = false;