diff --git a/src/librustc_ast_lowering/lib.rs b/src/librustc_ast_lowering/lib.rs
index 5cd869f60ab..b333053f601 100644
--- a/src/librustc_ast_lowering/lib.rs
+++ b/src/librustc_ast_lowering/lib.rs
@@ -36,7 +36,6 @@
 #![feature(specialization)]
 #![recursion_limit = "256"]
 
-use rustc::dep_graph::DepGraph;
 use rustc::hir::map::definitions::{DefKey, DefPathData, Definitions};
 use rustc_ast::ast;
 use rustc_ast::ast::*;
@@ -261,17 +260,11 @@ impl<'a> ImplTraitContext<'_, 'a> {
 
 pub fn lower_crate<'a, 'hir>(
     sess: &'a Session,
-    dep_graph: &'a DepGraph,
     krate: &'a Crate,
     resolver: &'a mut dyn Resolver,
     nt_to_tokenstream: NtToTokenstream,
     arena: &'hir Arena<'hir>,
 ) -> hir::Crate<'hir> {
-    // We're constructing the HIR here; we don't care what we will
-    // read, since we haven't even constructed the *input* to
-    // incr. comp. yet.
-    dep_graph.assert_ignored();
-
     let _prof_timer = sess.prof.verbose_generic_activity("hir_lowering");
 
     LoweringContext {
diff --git a/src/librustc_interface/passes.rs b/src/librustc_interface/passes.rs
index c331b1e3d1e..d3ed2fc89c1 100644
--- a/src/librustc_interface/passes.rs
+++ b/src/librustc_interface/passes.rs
@@ -439,10 +439,14 @@ pub fn lower_to_hir<'res, 'tcx>(
     krate: &'res ast::Crate,
     arena: &'tcx rustc_ast_lowering::Arena<'tcx>,
 ) -> Crate<'tcx> {
+    // We're constructing the HIR here; we don't care what we will
+    // read, since we haven't even constructed the *input* to
+    // incr. comp. yet.
+    dep_graph.assert_ignored();
+
     // Lower AST to HIR.
     let hir_crate = rustc_ast_lowering::lower_crate(
         sess,
-        &dep_graph,
         &krate,
         resolver,
         rustc_parse::nt_to_tokenstream,