2 files changed, 4 insertions, 2 deletions
diff --git a/compiler/rustc_incremental/src/persist/load.rs b/compiler/rustc_incremental/src/persist/load.rs
index 357f2ae92d4..26aaa24771f 100644
--- a/compiler/rustc_incremental/src/persist/load.rs
+++ b/compiler/rustc_incremental/src/persist/load.rs
@@ -11,6 +11,7 @@ use rustc_session::config::IncrementalStateAssertion;
 use rustc_session::Session;
 use rustc_span::ErrorGuaranteed;
 use std::path::{Path, PathBuf};
+use std::sync::Arc;
 
 use super::data::*;
 use super::file_format;
@@ -88,7 +89,7 @@ fn delete_dirty_work_product(sess: &Session, swp: SerializedWorkProduct) {
     work_product::delete_workproduct_files(sess, &swp.work_product);
 }
 
-fn load_dep_graph(sess: &Session) -> LoadResult<(SerializedDepGraph, WorkProductMap)> {
+fn load_dep_graph(sess: &Session) -> LoadResult<(Arc<SerializedDepGraph>, WorkProductMap)> {
     let prof = sess.prof.clone();
 
     if sess.opts.incremental.is_none() {
diff --git a/compiler/rustc_incremental/src/persist/save.rs b/compiler/rustc_incremental/src/persist/save.rs
index 32759f5284a..9777f769280 100644
--- a/compiler/rustc_incremental/src/persist/save.rs
+++ b/compiler/rustc_incremental/src/persist/save.rs
@@ -10,6 +10,7 @@ use rustc_serialize::opaque::{FileEncodeResult, FileEncoder};
 use rustc_serialize::Encodable as RustcEncodable;
 use rustc_session::Session;
 use std::fs;
+use std::sync::Arc;
 
 use super::data::*;
 use super::dirty_clean;
@@ -147,7 +148,7 @@ fn encode_query_cache(tcx: TyCtxt<'_>, encoder: FileEncoder) -> FileEncodeResult
 /// and moves it to the permanent dep-graph path
 pub(crate) fn build_dep_graph(
     sess: &Session,
-    prev_graph: SerializedDepGraph,
+    prev_graph: Arc<SerializedDepGraph>,
     prev_work_products: WorkProductMap,
 ) -> Option<DepGraph> {
     if sess.opts.incremental.is_none() {