diff --git a/src/librustc_trans/trans/callee.rs b/src/librustc_trans/trans/callee.rs
index 5e412baa9ce..06e3cba6be1 100644
--- a/src/librustc_trans/trans/callee.rs
+++ b/src/librustc_trans/trans/callee.rs
@@ -58,21 +58,21 @@ use syntax::codemap::DUMMY_SP;
 use syntax::errors;
 use syntax::ptr::P;
 
-pub enum CalleeData<'tcx> {
+pub enum CalleeData {
     /// Constructor for enum variant/tuple-like-struct.
     NamedTupleConstructor(Disr),
 
     /// Function pointer.
     Fn(ValueRef),
 
-    Intrinsic(ast::NodeId, &'tcx subst::Substs<'tcx>),
+    Intrinsic,
 
     /// Trait object found in the vtable at that index.
     Virtual(usize)
 }
 
 pub struct Callee<'tcx> {
-    pub data: CalleeData<'tcx>,
+    pub data: CalleeData,
     pub ty: Ty<'tcx>
 }
 
@@ -245,7 +245,7 @@ impl<'tcx> Callee<'tcx> {
                 }
                 _ => unreachable!("expected fn item type, found {}", self.ty)
             },
-            Intrinsic(..) => unreachable!("intrinsic {} getting reified", self.ty)
+            Intrinsic => unreachable!("intrinsic {} getting reified", self.ty)
         }
     }
 }
@@ -545,7 +545,7 @@ fn trans_call_inner<'a, 'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
     };
 
     match callee.data {
-        Intrinsic(node, substs) => {
+        Intrinsic => {
             assert!(abi == Abi::RustIntrinsic || abi == Abi::PlatformIntrinsic);
             assert!(dest.is_some());
 
@@ -557,10 +557,9 @@ fn trans_call_inner<'a, 'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
             };
 
             let arg_cleanup_scope = fcx.push_custom_cleanup_scope();
-            return intrinsic::trans_intrinsic_call(bcx, node, callee.ty,
+            return intrinsic::trans_intrinsic_call(bcx, callee.ty,
                                                    arg_cleanup_scope, args,
                                                    dest.unwrap(),
-                                                   substs,
                                                    call_info);
         }
         NamedTupleConstructor(disr) => {
diff --git a/src/librustc_trans/trans/intrinsic.rs b/src/librustc_trans/trans/intrinsic.rs
index 7494cf2975a..707d60e18a9 100644
--- a/src/librustc_trans/trans/intrinsic.rs
+++ b/src/librustc_trans/trans/intrinsic.rs
@@ -51,8 +51,8 @@ use syntax::codemap::Span;
 
 use std::cmp::Ordering;
 
-pub fn get_simple_intrinsic(ccx: &CrateContext, item: &hir::ForeignItem) -> Option<ValueRef> {
-    let name = match &*item.name.as_str() {
+fn get_simple_intrinsic(ccx: &CrateContext, name: &str) -> Option<ValueRef> {
+    let llvm_name = match name {
         "sqrtf32" => "llvm.sqrt.f32",
         "sqrtf64" => "llvm.sqrt.f64",
         "powif32" => "llvm.powi.f32",
@@ -94,7 +94,7 @@ pub fn get_simple_intrinsic(ccx: &CrateContext, item: &hir::ForeignItem) -> Opti
         "assume" => "llvm.assume",
         _ => return None
     };
-    Some(ccx.get_intrinsic(&name))
+    Some(ccx.get_intrinsic(&llvm_name))
 }
 
 pub fn span_transmute_size_error(a: &Session, b: Span, msg: &str) {
@@ -171,12 +171,10 @@ pub fn check_intrinsics(ccx: &CrateContext) {
 /// and in libcore/intrinsics.rs; if you need access to any llvm intrinsics,
 /// add them to librustc_trans/trans/context.rs
 pub fn trans_intrinsic_call<'a, 'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
-                                            node: ast::NodeId,
                                             callee_ty: Ty<'tcx>,
                                             cleanup_scope: cleanup::CustomScopeIndex,
                                             args: callee::CallArgs<'a, 'tcx>,
                                             dest: expr::Dest,
-                                            substs: &'tcx subst::Substs<'tcx>,
                                             call_info: NodeIdAndSpan)
                                             -> Result<'blk, 'tcx> {
     let fcx = bcx.fcx;
@@ -185,12 +183,16 @@ pub fn trans_intrinsic_call<'a, 'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
 
     let _icx = push_ctxt("trans_intrinsic_call");
 
-    let sig = ccx.tcx().erase_late_bound_regions(callee_ty.fn_sig());
-    let sig = infer::normalize_associated_type(ccx.tcx(), &sig);
+    let (def_id, substs, sig) = match callee_ty.sty {
+        ty::TyFnDef(def_id, substs, fty) => {
+            let sig = tcx.erase_late_bound_regions(&fty.sig);
+            (def_id, substs, infer::normalize_associated_type(tcx, &sig))
+        }
+        _ => unreachable!("expected fn item type, found {}", callee_ty)
+    };
     let arg_tys = sig.inputs;
     let ret_ty = sig.output;
-    let foreign_item = tcx.map.expect_foreign_item(node);
-    let name = foreign_item.name.as_str();
+    let name = tcx.item_name(def_id).as_str();
 
     let call_debug_location = DebugLoc::At(call_info.id, call_info.span);
 
@@ -437,8 +439,8 @@ pub fn trans_intrinsic_call<'a, 'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
         }
     };
 
-    let simple = get_simple_intrinsic(ccx, &foreign_item);
-    let llval = match (simple, &*name) {
+    let simple = get_simple_intrinsic(ccx, &name);
+    let llval = match (simple, &name[..]) {
         (Some(llfn), _) => {
             Call(bcx, llfn, &llargs, None, call_debug_location)
         }
@@ -815,8 +817,7 @@ pub fn trans_intrinsic_call<'a, 'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
         (_, _) => {
             let intr = match Intrinsic::find(tcx, &name) {
                 Some(intr) => intr,
-                None => ccx.sess().span_bug(foreign_item.span,
-                                            &format!("unknown intrinsic '{}'", name)),
+                None => unreachable!("unknown intrinsic '{}'", name),
             };
             fn one<T>(x: Vec<T>) -> T {
                 assert_eq!(x.len(), 1);