diff --git a/src/librustc/ich/impls_ty.rs b/src/librustc/ich/impls_ty.rs
index eec73937e2c..740b4c428dc 100644
--- a/src/librustc/ich/impls_ty.rs
+++ b/src/librustc/ich/impls_ty.rs
@@ -656,7 +656,7 @@ fn hash_stable<W: StableHasherResult>(&self,
 
             ich::hash_stable_itemlocalmap(hcx, hasher, closure_tys);
             ich::hash_stable_itemlocalmap(hcx, hasher, closure_kinds);
-            ich::hash_stable_nodemap(hcx, hasher, liberated_fn_sigs);
+            ich::hash_stable_itemlocalmap(hcx, hasher, liberated_fn_sigs);
             ich::hash_stable_nodemap(hcx, hasher, fru_field_types);
             ich::hash_stable_nodemap(hcx, hasher, cast_kinds);
 
diff --git a/src/librustc/ty/context.rs b/src/librustc/ty/context.rs
index 492ec0f3e40..5ec39b78e30 100644
--- a/src/librustc/ty/context.rs
+++ b/src/librustc/ty/context.rs
@@ -247,7 +247,7 @@ pub struct TypeckTables<'tcx> {
     /// (including late-bound regions) are replaced with free
     /// equivalents. This table is not used in trans (since regions
     /// are erased there) and hence is not serialized to metadata.
-    pub liberated_fn_sigs: NodeMap<ty::FnSig<'tcx>>,
+    pub liberated_fn_sigs: ItemLocalMap<ty::FnSig<'tcx>>,
 
     /// For each FRU expression, record the normalized types of the fields
     /// of the struct - this is needed because it is non-trivial to
@@ -285,7 +285,7 @@ pub fn empty(local_id_root: DefId) -> TypeckTables<'tcx> {
             upvar_capture_map: FxHashMap(),
             closure_tys: ItemLocalMap(),
             closure_kinds: ItemLocalMap(),
-            liberated_fn_sigs: NodeMap(),
+            liberated_fn_sigs: ItemLocalMap(),
             fru_field_types: NodeMap(),
             cast_kinds: NodeMap(),
             used_trait_imports: DefIdSet(),
diff --git a/src/librustc_mir/build/mod.rs b/src/librustc_mir/build/mod.rs
index 66817fda5b7..ae951d50a8c 100644
--- a/src/librustc_mir/build/mod.rs
+++ b/src/librustc_mir/build/mod.rs
@@ -90,7 +90,9 @@ pub fn mir_build<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId) -> Mir<'t
         } else if let MirSource::Fn(id) = src {
             // fetch the fully liberated fn signature (that is, all bound
             // types/lifetimes replaced)
-            let fn_sig = cx.tables().liberated_fn_sigs[&id].clone();
+            let fn_hir_id = tcx.hir.node_to_hir_id(id);
+            cx.tables().validate_hir_id(fn_hir_id);
+            let fn_sig = cx.tables().liberated_fn_sigs[&fn_hir_id.local_id].clone();
 
             let ty = tcx.type_of(tcx.hir.local_def_id(id));
             let mut abi = fn_sig.abi;
diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs
index 5308ffe6f8d..0d484d2ce36 100644
--- a/src/librustc_typeck/check/mod.rs
+++ b/src/librustc_typeck/check/mod.rs
@@ -1028,7 +1028,12 @@ fn check_fn<'a, 'gcx, 'tcx>(inherited: &'a Inherited<'a, 'gcx, 'tcx>,
         fcx.write_ty(arg.hir_id, arg_ty);
     }
 
-    inherited.tables.borrow_mut().liberated_fn_sigs.insert(fn_id, fn_sig);
+    {
+        let mut inh_tables = inherited.tables.borrow_mut();
+        let fn_hir_id = fcx.tcx.hir.node_to_hir_id(fn_id);
+        inh_tables.validate_hir_id(fn_hir_id);
+        inh_tables.liberated_fn_sigs.insert(fn_hir_id.local_id, fn_sig);
+    }
 
     fcx.check_return_expr(&body.value);
 
diff --git a/src/librustc_typeck/check/regionck.rs b/src/librustc_typeck/check/regionck.rs
index 3113f4a569f..c9c8f3363ce 100644
--- a/src/librustc_typeck/check/regionck.rs
+++ b/src/librustc_typeck/check/regionck.rs
@@ -309,8 +309,10 @@ fn visit_fn_body(&mut self,
         let old_call_site_scope = self.set_call_site_scope(Some(call_site));
 
         let fn_sig = {
-            let fn_sig_map = &self.tables.borrow().liberated_fn_sigs;
-            match fn_sig_map.get(&id) {
+            let tables = self.tables.borrow();
+            let fn_hir_id = self.tcx.hir.node_to_hir_id(id);
+            tables.validate_hir_id(fn_hir_id);
+            match tables.liberated_fn_sigs.get(&fn_hir_id.local_id) {
                 Some(f) => f.clone(),
                 None => {
                     bug!("No fn-sig entry for id={}", id);
diff --git a/src/librustc_typeck/check/writeback.rs b/src/librustc_typeck/check/writeback.rs
index ed7b75ddb05..499afe62b4f 100644
--- a/src/librustc_typeck/check/writeback.rs
+++ b/src/librustc_typeck/check/writeback.rs
@@ -348,9 +348,16 @@ fn visit_adjustments(&mut self, span: Span, hir_id: hir::HirId) {
     }
 
     fn visit_liberated_fn_sigs(&mut self) {
-        for (&node_id, fn_sig) in self.fcx.tables.borrow().liberated_fn_sigs.iter() {
-            let fn_sig = self.resolve(fn_sig, &node_id);
-            self.tables.liberated_fn_sigs.insert(node_id, fn_sig.clone());
+        let fcx_tables = self.fcx.tables.borrow();
+        debug_assert_eq!(fcx_tables.local_id_root, self.tables.local_id_root);
+
+        for (&local_id, fn_sig) in fcx_tables.liberated_fn_sigs.iter() {
+            let hir_id = hir::HirId {
+                owner: fcx_tables.local_id_root.index,
+                local_id,
+            };
+            let fn_sig = self.resolve(fn_sig, &hir_id);
+            self.tables.liberated_fn_sigs.insert(local_id, fn_sig.clone());
         }
     }