diff --git a/src/librustc/dep_graph/dep_node.rs b/src/librustc/dep_graph/dep_node.rs
index cb5680956bbd..76f31eb5596e 100644
--- a/src/librustc/dep_graph/dep_node.rs
+++ b/src/librustc/dep_graph/dep_node.rs
@@ -537,6 +537,8 @@ define_dep_nodes!( <'tcx>
     [] ImplDefaultness(DefId),
     [] ExportedSymbols(CrateNum),
     [] NativeLibraries(CrateNum),
+    [] PluginRegistrarFn(CrateNum),
+    [] DeriveRegistrarFn(CrateNum),
 );
 
 trait DepNodeParams<'a, 'gcx: 'tcx + 'a, 'tcx: 'a> : fmt::Debug {
diff --git a/src/librustc/middle/cstore.rs b/src/librustc/middle/cstore.rs
index edc046a12250..9294530f5152 100644
--- a/src/librustc/middle/cstore.rs
+++ b/src/librustc/middle/cstore.rs
@@ -255,8 +255,6 @@ pub trait CrateStore {
     fn original_crate_name(&self, cnum: CrateNum) -> Symbol;
     fn crate_hash(&self, cnum: CrateNum) -> Svh;
     fn crate_disambiguator(&self, cnum: CrateNum) -> Symbol;
-    fn plugin_registrar_fn(&self, cnum: CrateNum) -> Option<DefId>;
-    fn derive_registrar_fn(&self, cnum: CrateNum) -> Option<DefId>;
 
     // resolve
     fn def_key(&self, def: DefId) -> DefKey;
@@ -359,10 +357,6 @@ impl CrateStore for DummyCrateStore {
     fn crate_hash(&self, cnum: CrateNum) -> Svh { bug!("crate_hash") }
     fn crate_disambiguator(&self, cnum: CrateNum)
                            -> Symbol { bug!("crate_disambiguator") }
-    fn plugin_registrar_fn(&self, cnum: CrateNum) -> Option<DefId>
-        { bug!("plugin_registrar_fn") }
-    fn derive_registrar_fn(&self, cnum: CrateNum) -> Option<DefId>
-        { bug!("derive_registrar_fn") }
 
     // resolve
     fn def_key(&self, def: DefId) -> DefKey { bug!("def_key") }
diff --git a/src/librustc/ty/maps.rs b/src/librustc/ty/maps.rs
index c8ec111828e3..31a1f9aee4e3 100644
--- a/src/librustc/ty/maps.rs
+++ b/src/librustc/ty/maps.rs
@@ -599,6 +599,18 @@ impl<'tcx> QueryDescription for queries::native_libraries<'tcx> {
     }
 }
 
+impl<'tcx> QueryDescription for queries::plugin_registrar_fn<'tcx> {
+    fn describe(_tcx: TyCtxt, _: CrateNum) -> String {
+        format!("looking up the plugin registrar for a crate")
+    }
+}
+
+impl<'tcx> QueryDescription for queries::derive_registrar_fn<'tcx> {
+    fn describe(_tcx: TyCtxt, _: CrateNum) -> String {
+        format!("looking up the derive registrar for a crate")
+    }
+}
+
 // If enabled, send a message to the profile-queries thread
 macro_rules! profq_msg {
     ($tcx:expr, $msg:expr) => {
@@ -1177,6 +1189,8 @@ define_maps! { <'tcx>
     [] fn impl_defaultness: ImplDefaultness(DefId) -> hir::Defaultness,
     [] fn exported_symbols: ExportedSymbols(CrateNum) -> Rc<Vec<DefId>>,
     [] fn native_libraries: NativeLibraries(CrateNum) -> Rc<Vec<NativeLibrary>>,
+    [] fn plugin_registrar_fn: PluginRegistrarFn(CrateNum) -> Option<DefId>,
+    [] fn derive_registrar_fn: DeriveRegistrarFn(CrateNum) -> Option<DefId>,
 }
 
 fn type_param_predicates<'tcx>((item_id, param_id): (DefId, DefId)) -> DepConstructor<'tcx> {
diff --git a/src/librustc_lint/builtin.rs b/src/librustc_lint/builtin.rs
index 780d34d57017..27ee8fd5cddb 100644
--- a/src/librustc_lint/builtin.rs
+++ b/src/librustc_lint/builtin.rs
@@ -1064,7 +1064,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for PluginAsLibrary {
         };
 
         let prfn = match cx.sess().cstore.extern_mod_stmt_cnum(it.id) {
-            Some(cnum) => cx.sess().cstore.plugin_registrar_fn(cnum),
+            Some(cnum) => cx.tcx.plugin_registrar_fn(cnum),
             None => {
                 // Probably means we aren't linking the crate for some reason.
                 //
diff --git a/src/librustc_metadata/cstore_impl.rs b/src/librustc_metadata/cstore_impl.rs
index 537154b4a4ca..842335212eed 100644
--- a/src/librustc_metadata/cstore_impl.rs
+++ b/src/librustc_metadata/cstore_impl.rs
@@ -165,6 +165,16 @@ provide! { <'tcx> tcx, def_id, cdata,
     impl_defaultness => { cdata.get_impl_defaultness(def_id.index) }
     exported_symbols => { Rc::new(cdata.get_exported_symbols(&tcx.dep_graph)) }
     native_libraries => { Rc::new(cdata.get_native_libraries(&tcx.dep_graph)) }
+    plugin_registrar_fn => {
+        cdata.root.plugin_registrar_fn.map(|index| {
+            DefId { krate: def_id.krate, index }
+        })
+    }
+    derive_registrar_fn => {
+        cdata.root.macro_derive_registrar.map(|index| {
+            DefId { krate: def_id.krate, index }
+        })
+    }
 }
 
 pub fn provide_local<'tcx>(providers: &mut Providers<'tcx>) {
@@ -283,22 +293,6 @@ impl CrateStore for cstore::CStore {
         self.get_crate_data(cnum).disambiguator()
     }
 
-    fn plugin_registrar_fn(&self, cnum: CrateNum) -> Option<DefId>
-    {
-        self.get_crate_data(cnum).root.plugin_registrar_fn.map(|index| DefId {
-            krate: cnum,
-            index,
-        })
-    }
-
-    fn derive_registrar_fn(&self, cnum: CrateNum) -> Option<DefId>
-    {
-        self.get_crate_data(cnum).root.macro_derive_registrar.map(|index| DefId {
-            krate: cnum,
-            index,
-        })
-    }
-
     /// Returns the `DefKey` for a given `DefId`. This indicates the
     /// parent `DefId` as well as some idea of what kind of data the
     /// `DefId` refers to.
diff --git a/src/librustc_trans/back/symbol_export.rs b/src/librustc_trans/back/symbol_export.rs
index f1b18c64dcb9..68f30b589c2c 100644
--- a/src/librustc_trans/back/symbol_export.rs
+++ b/src/librustc_trans/back/symbol_export.rs
@@ -115,8 +115,8 @@ impl ExportedSymbols {
 
             // If this crate is a plugin and/or a custom derive crate, then
             // we're not even going to link those in so we skip those crates.
-            if tcx.sess.cstore.plugin_registrar_fn(cnum).is_some() ||
-               tcx.sess.cstore.derive_registrar_fn(cnum).is_some() {
+            if tcx.plugin_registrar_fn(cnum).is_some() ||
+               tcx.derive_registrar_fn(cnum).is_some() {
                 continue;
             }