diff --git a/rust-toolchain b/rust-toolchain
index ce197494..c89be302 100644
--- a/rust-toolchain
+++ b/rust-toolchain
@@ -1 +1 @@
-nightly-2020-07-28
+nightly-2020-08-07
diff --git a/src/traverse.rs b/src/traverse.rs
index e5efe3c4..47713b56 100644
--- a/src/traverse.rs
+++ b/src/traverse.rs
@@ -1147,7 +1147,7 @@ fn diff_trait_impls<'tcx>(
     let to_new = TranslationContext::target_new(tcx, id_mapping, false);
     let to_old = TranslationContext::target_old(tcx, id_mapping, false);
 
-    for old_impl_def_id in tcx
+    for (old_impl_def_id, _) in tcx
         .all_trait_implementations(id_mapping.get_old_crate())
         .iter()
     {
@@ -1167,7 +1167,7 @@ fn diff_trait_impls<'tcx>(
         }
     }
 
-    for new_impl_def_id in tcx
+    for (new_impl_def_id, _) in tcx
         .all_trait_implementations(id_mapping.get_new_crate())
         .iter()
     {