diff --git a/src/librustc/ty/layout.rs b/src/librustc/ty/layout.rs
index c3cd65230bd86..5069c59562678 100644
--- a/src/librustc/ty/layout.rs
+++ b/src/librustc/ty/layout.rs
@@ -1203,7 +1203,7 @@ impl<'a, 'tcx> LayoutCx<'tcx, TyCtxt<'a, 'tcx, 'tcx>> {
                 }
 
                 let pointee = tcx.normalize_associated_type_in_env(&pointee, param_env);
-                if pointee.is_sized(tcx, param_env, DUMMY_SP) {
+                if pointee.is_sized(tcx.at(DUMMY_SP), param_env) {
                     return Ok(tcx.intern_layout(LayoutDetails::scalar(self, data_ptr)));
                 }
 
@@ -1428,7 +1428,7 @@ impl<'a, 'tcx> LayoutCx<'tcx, TyCtxt<'a, 'tcx, 'tcx>> {
                         let param_env = tcx.param_env(def.did);
                         let last_field = def.variants[v].fields.last().unwrap();
                         let always_sized = tcx.type_of(last_field.did)
-                          .is_sized(tcx, param_env, DUMMY_SP);
+                          .is_sized(tcx.at(DUMMY_SP), param_env);
                         if !always_sized { StructKind::MaybeUnsized }
                         else { StructKind::AlwaysSized }
                     };
diff --git a/src/librustc/ty/util.rs b/src/librustc/ty/util.rs
index 47ad7cbcb56f7..3a5e6d97cd4ba 100644
--- a/src/librustc/ty/util.rs
+++ b/src/librustc/ty/util.rs
@@ -20,6 +20,7 @@ use traits::{self, Reveal};
 use ty::{self, Ty, TyCtxt, TypeFoldable};
 use ty::fold::TypeVisitor;
 use ty::subst::{Subst, UnpackedKind};
+use ty::maps::TyCtxtAt;
 use ty::TypeVariants::*;
 use util::common::ErrorReported;
 use middle::lang_items;
@@ -864,11 +865,10 @@ impl<'a, 'tcx> ty::TyS<'tcx> {
     }
 
     pub fn is_sized(&'tcx self,
-                    tcx: TyCtxt<'a, 'tcx, 'tcx>,
-                    param_env: ty::ParamEnv<'tcx>,
-                    span: Span)-> bool
+                    tcx_at: TyCtxtAt<'a, 'tcx, 'tcx>,
+                    param_env: ty::ParamEnv<'tcx>)-> bool
     {
-        tcx.at(span).is_sized_raw(param_env.and(self))
+        tcx_at.is_sized_raw(param_env.and(self))
     }
 
     pub fn is_freeze(&'tcx self,
diff --git a/src/librustc_mir/borrow_check/nll/type_check/mod.rs b/src/librustc_mir/borrow_check/nll/type_check/mod.rs
index 3af10c5c25169..bbf4357e5b0f9 100644
--- a/src/librustc_mir/borrow_check/nll/type_check/mod.rs
+++ b/src/librustc_mir/borrow_check/nll/type_check/mod.rs
@@ -1208,7 +1208,7 @@ impl<'a, 'gcx, 'tcx> TypeChecker<'a, 'gcx, 'tcx> {
         // shouldn't affect `is_sized`.
         let gcx = self.tcx().global_tcx();
         let erased_ty = gcx.lift(&self.tcx().erase_regions(&ty)).unwrap();
-        if !erased_ty.is_sized(gcx, self.param_env, span) {
+        if !erased_ty.is_sized(gcx.at(span), self.param_env) {
             // in current MIR construction, all non-control-flow rvalue
             // expressions evaluate through `as_temp` or `into` a return
             // slot or local, so to find all unsized rvalues it is enough
diff --git a/src/librustc_mir/interpret/eval_context.rs b/src/librustc_mir/interpret/eval_context.rs
index 08c16fed5dd3f..25f933c5da6e7 100644
--- a/src/librustc_mir/interpret/eval_context.rs
+++ b/src/librustc_mir/interpret/eval_context.rs
@@ -286,7 +286,7 @@ impl<'a, 'tcx, M: Machine<'tcx>> EvalContext<'a, 'tcx, M> {
     }
 
     pub(super) fn type_is_sized(&self, ty: Ty<'tcx>) -> bool {
-        ty.is_sized(self.tcx, self.param_env, DUMMY_SP)
+        ty.is_sized(self.tcx.at(DUMMY_SP), self.param_env)
     }
 
     pub fn load_mir(
diff --git a/src/librustc_mir/monomorphize/collector.rs b/src/librustc_mir/monomorphize/collector.rs
index 10c2f9f758f14..1fba436d40578 100644
--- a/src/librustc_mir/monomorphize/collector.rs
+++ b/src/librustc_mir/monomorphize/collector.rs
@@ -796,7 +796,7 @@ fn find_vtable_types_for_unsizing<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
     let ptr_vtable = |inner_source: Ty<'tcx>, inner_target: Ty<'tcx>| {
         let type_has_metadata = |ty: Ty<'tcx>| -> bool {
             use syntax_pos::DUMMY_SP;
-            if ty.is_sized(tcx, ty::ParamEnv::empty(traits::Reveal::All), DUMMY_SP) {
+            if ty.is_sized(tcx.at(DUMMY_SP), ty::ParamEnv::empty(traits::Reveal::All)) {
                 return false;
             }
             let tail = tcx.struct_tail(ty);
diff --git a/src/librustc_trans/common.rs b/src/librustc_trans/common.rs
index 37bd225a7d9cb..7c4e2340d5bdc 100644
--- a/src/librustc_trans/common.rs
+++ b/src/librustc_trans/common.rs
@@ -44,7 +44,7 @@ pub fn type_needs_drop<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, ty: Ty<'tcx>) -> b
 }
 
 pub fn type_is_sized<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, ty: Ty<'tcx>) -> bool {
-    ty.is_sized(tcx, ty::ParamEnv::empty(traits::Reveal::All), DUMMY_SP)
+    ty.is_sized(tcx.at(DUMMY_SP), ty::ParamEnv::empty(traits::Reveal::All))
 }
 
 pub fn type_is_freeze<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, ty: Ty<'tcx>) -> bool {
diff --git a/src/librustc_trans/context.rs b/src/librustc_trans/context.rs
index b93e8c2ad21ca..dc5e788959448 100644
--- a/src/librustc_trans/context.rs
+++ b/src/librustc_trans/context.rs
@@ -435,7 +435,7 @@ impl<'b, 'tcx> CodegenCx<'b, 'tcx> {
 
     pub fn type_has_metadata(&self, ty: Ty<'tcx>) -> bool {
         use syntax_pos::DUMMY_SP;
-        if ty.is_sized(self.tcx, ty::ParamEnv::empty(traits::Reveal::All), DUMMY_SP) {
+        if ty.is_sized(self.tcx.at(DUMMY_SP), ty::ParamEnv::empty(traits::Reveal::All)) {
             return false;
         }