diff --git a/compiler/rustc_metadata/src/foreign_modules.rs b/compiler/rustc_metadata/src/foreign_modules.rs
index 5b42f48a7d466..c70a691452018 100644
--- a/compiler/rustc_metadata/src/foreign_modules.rs
+++ b/compiler/rustc_metadata/src/foreign_modules.rs
@@ -13,7 +13,7 @@ struct Collector {
     modules: Vec<ForeignModule>,
 }
 
-impl ItemLikeVisitor<'tcx> for Collector {
+impl<'tcx> ItemLikeVisitor<'tcx> for Collector {
     fn visit_item(&mut self, it: &'tcx hir::Item<'tcx>) {
         let items = match it.kind {
             hir::ItemKind::ForeignMod { items, .. } => items,
diff --git a/compiler/rustc_metadata/src/lib.rs b/compiler/rustc_metadata/src/lib.rs
index 0bf6c266b80e0..918c3b9daf107 100644
--- a/compiler/rustc_metadata/src/lib.rs
+++ b/compiler/rustc_metadata/src/lib.rs
@@ -1,7 +1,6 @@
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![feature(crate_visibility_modifier)]
 #![feature(drain_filter)]
-#![feature(in_band_lifetimes)]
 #![feature(let_else)]
 #![feature(nll)]
 #![feature(once_cell)]
diff --git a/compiler/rustc_metadata/src/locator.rs b/compiler/rustc_metadata/src/locator.rs
index e2fd8056f1a7c..2893ceb5bf543 100644
--- a/compiler/rustc_metadata/src/locator.rs
+++ b/compiler/rustc_metadata/src/locator.rs
@@ -734,7 +734,7 @@ impl<'a> CrateLocator<'a> {
     }
 }
 
-fn get_metadata_section(
+fn get_metadata_section<'p>(
     target: &Target,
     flavor: CrateFlavor,
     filename: &'p Path,
diff --git a/compiler/rustc_metadata/src/native_libs.rs b/compiler/rustc_metadata/src/native_libs.rs
index 9adf9406f09b4..808151089df85 100644
--- a/compiler/rustc_metadata/src/native_libs.rs
+++ b/compiler/rustc_metadata/src/native_libs.rs
@@ -31,7 +31,7 @@ struct Collector<'tcx> {
     libs: Vec<NativeLib>,
 }
 
-impl ItemLikeVisitor<'tcx> for Collector<'tcx> {
+impl<'tcx> ItemLikeVisitor<'tcx> for Collector<'tcx> {
     fn visit_item(&mut self, it: &'tcx hir::Item<'tcx>) {
         let (abi, foreign_mod_items) = match it.kind {
             hir::ItemKind::ForeignMod { abi, items } => (abi, items),
@@ -223,7 +223,7 @@ impl ItemLikeVisitor<'tcx> for Collector<'tcx> {
     fn visit_foreign_item(&mut self, _it: &'tcx hir::ForeignItem<'tcx>) {}
 }
 
-impl Collector<'tcx> {
+impl Collector<'_> {
     fn register_native_lib(&mut self, span: Option<Span>, lib: NativeLib) {
         if lib.name.as_ref().map_or(false, |&s| s == kw::Empty) {
             match span {
diff --git a/compiler/rustc_metadata/src/rmeta/decoder.rs b/compiler/rustc_metadata/src/rmeta/decoder.rs
index b2c7818a54218..09c6cb010b04d 100644
--- a/compiler/rustc_metadata/src/rmeta/decoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/decoder.rs
@@ -628,7 +628,7 @@ where
 
 implement_ty_decoder!(DecodeContext<'a, 'tcx>);
 
-impl MetadataBlob {
+impl<'tcx> MetadataBlob {
     crate fn new(metadata_ref: MetadataRef) -> MetadataBlob {
         MetadataBlob(Lrc::new(metadata_ref))
     }
@@ -697,7 +697,7 @@ impl CrateRoot<'_> {
         &self.triple
     }
 
-    crate fn decode_crate_deps(
+    crate fn decode_crate_deps<'a>(
         &self,
         metadata: &'a MetadataBlob,
     ) -> impl ExactSizeIterator<Item = CrateDep> + Captures<'a> {
diff --git a/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs b/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
index eeb0a77adc0ad..5ba7efc37f8bd 100644
--- a/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
+++ b/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
@@ -83,7 +83,7 @@ impl IntoArgs for (CrateNum, DefId) {
     }
 }
 
-impl IntoArgs for ty::InstanceDef<'tcx> {
+impl<'tcx> IntoArgs for ty::InstanceDef<'tcx> {
     fn into_args(self) -> (DefId, DefId) {
         (self.def_id(), self.def_id())
     }
diff --git a/compiler/rustc_metadata/src/rmeta/def_path_hash_map.rs b/compiler/rustc_metadata/src/rmeta/def_path_hash_map.rs
index d6435bb649d6d..054431169a26c 100644
--- a/compiler/rustc_metadata/src/rmeta/def_path_hash_map.rs
+++ b/compiler/rustc_metadata/src/rmeta/def_path_hash_map.rs
@@ -11,7 +11,7 @@ crate enum DefPathHashMapRef<'tcx> {
     BorrowedFromTcx(&'tcx DefPathHashMap),
 }
 
-impl DefPathHashMapRef<'tcx> {
+impl DefPathHashMapRef<'_> {
     #[inline]
     pub fn def_path_hash_to_def_index(&self, def_path_hash: &DefPathHash) -> DefIndex {
         match *self {
diff --git a/compiler/rustc_metadata/src/rmeta/encoder.rs b/compiler/rustc_metadata/src/rmeta/encoder.rs
index 7500df896e971..a6828e103dc5f 100644
--- a/compiler/rustc_metadata/src/rmeta/encoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/encoder.rs
@@ -964,7 +964,7 @@ fn should_encode_generics(def_kind: DefKind) -> bool {
     }
 }
 
-impl EncodeContext<'a, 'tcx> {
+impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
     fn encode_def_ids(&mut self) {
         if self.is_proc_macro {
             return;
@@ -1894,7 +1894,7 @@ impl EncodeContext<'a, 'tcx> {
 }
 
 // FIXME(eddyb) make metadata encoding walk over all definitions, instead of HIR.
-impl Visitor<'tcx> for EncodeContext<'a, 'tcx> {
+impl<'a, 'tcx> Visitor<'tcx> for EncodeContext<'a, 'tcx> {
     type Map = Map<'tcx>;
 
     fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
@@ -1927,7 +1927,7 @@ impl Visitor<'tcx> for EncodeContext<'a, 'tcx> {
     }
 }
 
-impl EncodeContext<'a, 'tcx> {
+impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
     fn encode_fields(&mut self, adt_def: &ty::AdtDef) {
         for (variant_index, variant) in adt_def.variants.iter_enumerated() {
             for (field_index, _field) in variant.fields.iter().enumerate() {
diff --git a/compiler/rustc_metadata/src/rmeta/mod.rs b/compiler/rustc_metadata/src/rmeta/mod.rs
index a65b5dade3e56..5ce239ac70426 100644
--- a/compiler/rustc_metadata/src/rmeta/mod.rs
+++ b/compiler/rustc_metadata/src/rmeta/mod.rs
@@ -275,7 +275,7 @@ macro_rules! define_tables {
             $($name: TableBuilder<$IDX, $T>),+
         }
 
-        impl TableBuilders<'tcx> {
+        impl<'tcx> TableBuilders<'tcx> {
             fn encode(&self, buf: &mut Encoder) -> LazyTables<'tcx> {
                 LazyTables {
                     $($name: self.$name.encode(buf)),+