diff --git a/src/librustc_metadata/rmeta/encoder.rs b/src/librustc_metadata/rmeta/encoder.rs
index 9410b19064683..8074bde61237d 100644
--- a/src/librustc_metadata/rmeta/encoder.rs
+++ b/src/librustc_metadata/rmeta/encoder.rs
@@ -1,5 +1,5 @@
 use crate::rmeta::*;
-use crate::rmeta::table::{FixedSizeEncoding, TableBuilder};
+use crate::rmeta::table::FixedSizeEncoding;
 
 use rustc::middle::cstore::{LinkagePreference, NativeLibrary,
                             EncodedMetadata, ForeignModule};
@@ -8,7 +8,7 @@ use rustc::hir::def_id::{CrateNum, CRATE_DEF_INDEX, DefIndex, DefId, LocalDefId,
 use rustc::hir::{GenericParamKind, AnonConst};
 use rustc::hir::map::definitions::DefPathTable;
 use rustc_data_structures::fingerprint::Fingerprint;
-use rustc_index::vec::{Idx, IndexVec};
+use rustc_index::vec::Idx;
 use rustc::middle::dependency_format::Linkage;
 use rustc::middle::exported_symbols::{ExportedSymbol, SymbolExportLevel,
                                       metadata_symbol_name};
@@ -60,30 +60,6 @@ struct EncodeContext<'tcx> {
     source_file_cache: Lrc<SourceFile>,
 }
 
-#[derive(Default)]
-struct PerDefTableBuilders<'tcx> {
-    kind: TableBuilder<DefIndex, Lazy<EntryKind<'tcx>>>,
-    visibility: TableBuilder<DefIndex, Lazy<ty::Visibility>>,
-    span: TableBuilder<DefIndex, Lazy<Span>>,
-    attributes: TableBuilder<DefIndex, Lazy<[ast::Attribute]>>,
-    children: TableBuilder<DefIndex, Lazy<[DefIndex]>>,
-    stability: TableBuilder<DefIndex, Lazy<attr::Stability>>,
-    deprecation: TableBuilder<DefIndex, Lazy<attr::Deprecation>>,
-
-    ty: TableBuilder<DefIndex, Lazy<Ty<'tcx>>>,
-    fn_sig: TableBuilder<DefIndex, Lazy<ty::PolyFnSig<'tcx>>>,
-    impl_trait_ref: TableBuilder<DefIndex, Lazy<ty::TraitRef<'tcx>>>,
-    inherent_impls: TableBuilder<DefIndex, Lazy<[DefIndex]>>,
-    variances: TableBuilder<DefIndex, Lazy<[ty::Variance]>>,
-    generics: TableBuilder<DefIndex, Lazy<ty::Generics>>,
-    explicit_predicates: TableBuilder<DefIndex, Lazy<ty::GenericPredicates<'tcx>>>,
-    inferred_outlives: TableBuilder<DefIndex, Lazy<&'tcx [(ty::Predicate<'tcx>, Span)]>>,
-    super_predicates: TableBuilder<DefIndex, Lazy<ty::GenericPredicates<'tcx>>>,
-
-    mir: TableBuilder<DefIndex, Lazy<mir::Body<'tcx>>>,
-    promoted_mir: TableBuilder<DefIndex, Lazy<IndexVec<mir::Promoted, mir::Body<'tcx>>>>,
-}
-
 macro_rules! encoder_methods {
     ($($name:ident($ty:ty);)*) => {
         $(fn $name(&mut self, value: $ty) -> Result<(), Self::Error> {
@@ -509,28 +485,7 @@ impl<'tcx> EncodeContext<'tcx> {
 
 
         i = self.position();
-        let per_def = LazyPerDefTables {
-            kind: self.per_def.kind.encode(&mut self.opaque),
-            visibility: self.per_def.visibility.encode(&mut self.opaque),
-            span: self.per_def.span.encode(&mut self.opaque),
-            attributes: self.per_def.attributes.encode(&mut self.opaque),
-            children: self.per_def.children.encode(&mut self.opaque),
-            stability: self.per_def.stability.encode(&mut self.opaque),
-            deprecation: self.per_def.deprecation.encode(&mut self.opaque),
-
-            ty: self.per_def.ty.encode(&mut self.opaque),
-            fn_sig: self.per_def.fn_sig.encode(&mut self.opaque),
-            impl_trait_ref: self.per_def.impl_trait_ref.encode(&mut self.opaque),
-            inherent_impls: self.per_def.inherent_impls.encode(&mut self.opaque),
-            variances: self.per_def.variances.encode(&mut self.opaque),
-            generics: self.per_def.generics.encode(&mut self.opaque),
-            explicit_predicates: self.per_def.explicit_predicates.encode(&mut self.opaque),
-            inferred_outlives: self.per_def.inferred_outlives.encode(&mut self.opaque),
-            super_predicates: self.per_def.super_predicates.encode(&mut self.opaque),
-
-            mir: self.per_def.mir.encode(&mut self.opaque),
-            promoted_mir: self.per_def.promoted_mir.encode(&mut self.opaque),
-        };
+        let per_def = self.per_def.encode(&mut self.opaque);
         let per_def_bytes = self.position() - i;
 
         // Encode the proc macro data
diff --git a/src/librustc_metadata/rmeta/mod.rs b/src/librustc_metadata/rmeta/mod.rs
index a17809b24c0ff..1bca2836a3a07 100644
--- a/src/librustc_metadata/rmeta/mod.rs
+++ b/src/librustc_metadata/rmeta/mod.rs
@@ -1,5 +1,5 @@
 use decoder::Metadata;
-use table::Table;
+use table::{Table, TableBuilder};
 
 use rustc::hir;
 use rustc::hir::def::{self, CtorKind};
@@ -15,6 +15,7 @@ use rustc_target::spec::{PanicStrategy, TargetTriple};
 use rustc_index::vec::IndexVec;
 use rustc_data_structures::svh::Svh;
 use rustc_data_structures::sync::MetadataRef;
+use rustc_serialize::opaque::Encoder;
 use syntax::{ast, attr};
 use syntax::edition::Edition;
 use syntax::symbol::Symbol;
@@ -230,31 +231,53 @@ crate struct TraitImpls {
     impls: Lazy<[DefIndex]>,
 }
 
-#[derive(RustcEncodable, RustcDecodable)]
-crate struct LazyPerDefTables<'tcx> {
-    kind: Lazy!(Table<DefIndex, Lazy!(EntryKind<'tcx>)>),
-    visibility: Lazy!(Table<DefIndex, Lazy<ty::Visibility>>),
-    span: Lazy!(Table<DefIndex, Lazy<Span>>),
-    attributes: Lazy!(Table<DefIndex, Lazy<[ast::Attribute]>>),
-    children: Lazy!(Table<DefIndex, Lazy<[DefIndex]>>),
-    stability: Lazy!(Table<DefIndex, Lazy<attr::Stability>>),
-    deprecation: Lazy!(Table<DefIndex, Lazy<attr::Deprecation>>),
-    ty: Lazy!(Table<DefIndex, Lazy!(Ty<'tcx>)>),
-    fn_sig: Lazy!(Table<DefIndex, Lazy!(ty::PolyFnSig<'tcx>)>),
-    impl_trait_ref: Lazy!(Table<DefIndex, Lazy!(ty::TraitRef<'tcx>)>),
-    inherent_impls: Lazy!(Table<DefIndex, Lazy<[DefIndex]>>),
-    variances: Lazy!(Table<DefIndex, Lazy<[ty::Variance]>>),
-    generics: Lazy!(Table<DefIndex, Lazy<ty::Generics>>),
-    explicit_predicates: Lazy!(Table<DefIndex, Lazy!(ty::GenericPredicates<'tcx>)>),
+/// Define `LazyPerDefTables` and `PerDefTableBuilders` at the same time.
+macro_rules! define_per_def_tables {
+    ($($name:ident: Table<DefIndex, $T:ty>),+ $(,)?) => {
+        #[derive(RustcEncodable, RustcDecodable)]
+        crate struct LazyPerDefTables<'tcx> {
+            $($name: Lazy!(Table<DefIndex, $T>)),+
+        }
+
+        #[derive(Default)]
+        struct PerDefTableBuilders<'tcx> {
+            $($name: TableBuilder<DefIndex, $T>),+
+        }
+
+        impl PerDefTableBuilders<'tcx> {
+            fn encode(&self, buf: &mut Encoder) -> LazyPerDefTables<'tcx> {
+                LazyPerDefTables {
+                    $($name: self.$name.encode(buf)),+
+                }
+            }
+        }
+    }
+}
+
+define_per_def_tables! {
+    kind: Table<DefIndex, Lazy!(EntryKind<'tcx>)>,
+    visibility: Table<DefIndex, Lazy<ty::Visibility>>,
+    span: Table<DefIndex, Lazy<Span>>,
+    attributes: Table<DefIndex, Lazy<[ast::Attribute]>>,
+    children: Table<DefIndex, Lazy<[DefIndex]>>,
+    stability: Table<DefIndex, Lazy<attr::Stability>>,
+    deprecation: Table<DefIndex, Lazy<attr::Deprecation>>,
+    ty: Table<DefIndex, Lazy!(Ty<'tcx>)>,
+    fn_sig: Table<DefIndex, Lazy!(ty::PolyFnSig<'tcx>)>,
+    impl_trait_ref: Table<DefIndex, Lazy!(ty::TraitRef<'tcx>)>,
+    inherent_impls: Table<DefIndex, Lazy<[DefIndex]>>,
+    variances: Table<DefIndex, Lazy<[ty::Variance]>>,
+    generics: Table<DefIndex, Lazy<ty::Generics>>,
+    explicit_predicates: Table<DefIndex, Lazy!(ty::GenericPredicates<'tcx>)>,
     // FIXME(eddyb) this would ideally be `Lazy<[...]>` but `ty::Predicate`
     // doesn't handle shorthands in its own (de)serialization impls,
     // as it's an `enum` for which we want to derive (de)serialization,
     // so the `ty::codec` APIs handle the whole `&'tcx [...]` at once.
     // Also, as an optimization, a missing entry indicates an empty `&[]`.
-    inferred_outlives: Lazy!(Table<DefIndex, Lazy!(&'tcx [(ty::Predicate<'tcx>, Span)])>),
-    super_predicates: Lazy!(Table<DefIndex, Lazy!(ty::GenericPredicates<'tcx>)>),
-    mir: Lazy!(Table<DefIndex, Lazy!(mir::Body<'tcx>)>),
-    promoted_mir: Lazy!(Table<DefIndex, Lazy!(IndexVec<mir::Promoted, mir::Body<'tcx>>)>),
+    inferred_outlives: Table<DefIndex, Lazy!(&'tcx [(ty::Predicate<'tcx>, Span)])>,
+    super_predicates: Table<DefIndex, Lazy!(ty::GenericPredicates<'tcx>)>,
+    mir: Table<DefIndex, Lazy!(mir::Body<'tcx>)>,
+    promoted_mir: Table<DefIndex, Lazy!(IndexVec<mir::Promoted, mir::Body<'tcx>>)>,
 }
 
 #[derive(Copy, Clone, RustcEncodable, RustcDecodable)]