diff --git a/src/librustc_incremental/persist/load.rs b/src/librustc_incremental/persist/load.rs
index 142367e08ee..7cf53b37b1c 100644
--- a/src/librustc_incremental/persist/load.rs
+++ b/src/librustc_incremental/persist/load.rs
@@ -41,6 +41,7 @@ pub fn load_dep_graph<'tcx>(tcx: &ty::TyCtxt<'tcx>) {
     let _ignore = tcx.dep_graph.in_ignore();
 
     if let Some(dep_graph) = dep_graph_path(tcx) {
+        // FIXME(#32754) lock file?
         load_dep_graph_if_exists(tcx, &dep_graph);
         dirty_clean::check_dirty_clean_annotations(tcx);
     }
diff --git a/src/librustc_incremental/persist/save.rs b/src/librustc_incremental/persist/save.rs
index 692d51aa256..1db129ca700 100644
--- a/src/librustc_incremental/persist/save.rs
+++ b/src/librustc_incremental/persist/save.rs
@@ -24,6 +24,8 @@ pub fn save_dep_graph<'tcx>(tcx: &ty::TyCtxt<'tcx>) {
     let _ignore = tcx.dep_graph.in_ignore();
 
     if let Some(dep_graph) = dep_graph_path(tcx) {
+        // FIXME(#32754) lock file?
+
         // delete the old dep-graph, if any
         if dep_graph.exists() {
             match fs::remove_file(&dep_graph) {