diff --git a/src/librustc/front/intrinsic.rs b/src/librustc/front/intrinsic.rs
index fcb08180a5ea..f19e37062535 100644
--- a/src/librustc/front/intrinsic.rs
+++ b/src/librustc/front/intrinsic.rs
@@ -20,14 +20,22 @@ pub mod intrinsic {
     // version in sys is no longer present.
     pub fn get_tydesc<T>() -> *TyDesc {
         unsafe {
-            rusti::get_tydesc::<T>() as *TyDesc
+            rusti::get_tydesc::<T>()
         }
     }
 
+    pub type GlueFn = extern "Rust" fn(**TyDesc, *i8);
+
+    // NB: this has to be kept in sync with the Rust ABI.
     pub struct TyDesc {
         size: uint,
-        align: uint
-        // Remaining fields not listed
+        align: uint,
+        take_glue: GlueFn,
+        drop_glue: GlueFn,
+        free_glue: GlueFn,
+        visit_glue: GlueFn,
+        shape: *i8,
+        shape_tables: *i8
     }
 
     pub enum Opaque { }
@@ -133,7 +141,7 @@ pub mod intrinsic {
 
         #[abi = "rust-intrinsic"]
         pub extern "rust-intrinsic" {
-            pub fn get_tydesc<T>() -> *();
+            pub fn get_tydesc<T>() -> *TyDesc;
             pub fn visit_tydesc(td: *TyDesc, tv: @TyVisitor);
         }
     }
diff --git a/src/librustc/middle/trans/foreign.rs b/src/librustc/middle/trans/foreign.rs
index 10e63e6af777..855610510bd9 100644
--- a/src/librustc/middle/trans/foreign.rs
+++ b/src/librustc/middle/trans/foreign.rs
@@ -681,9 +681,12 @@ pub fn trans_intrinsic(ccx: @mut CrateContext,
             let static_ti = get_tydesc(ccx, tp_ty);
             glue::lazily_emit_all_tydesc_glue(ccx, static_ti);
 
-            // FIXME (#3727): change this to ccx.tydesc_ty.ptr_to() when the
-            // core::sys copy of the get_tydesc interface dies off.
-            let td = PointerCast(bcx, static_ti.tydesc, Type::nil().ptr_to());
+            // FIXME (#3730): ideally this shouldn't need a cast,
+            // but there's a circularity between translating rust types to llvm
+            // types and having a tydesc type available. So I can't directly access
+            // the llvm type of intrinsic::TyDesc struct.
+            let userland_tydesc_ty = type_of::type_of(ccx, output_type);
+            let td = PointerCast(bcx, static_ti.tydesc, userland_tydesc_ty);
             Store(bcx, td, fcx.llretptr.get());
         }
         "init" => {
diff --git a/src/librustc/middle/trans/glue.rs b/src/librustc/middle/trans/glue.rs
index e9febb51005c..0930d3550353 100644
--- a/src/librustc/middle/trans/glue.rs
+++ b/src/librustc/middle/trans/glue.rs
@@ -789,7 +789,6 @@ pub fn emit_tydescs(ccx: &mut CrateContext) {
     };
 }
 
-fn type_of_glue_fn(ccx: &CrateContext) -> Type {
-    let tydescpp = ccx.tydesc_type.ptr_to().ptr_to();
-    Type::func([ Type::nil().ptr_to(), tydescpp, Type::i8p() ], &Type::void())
+pub fn type_of_glue_fn(ccx: &CrateContext) -> Type {
+    Type::glue_fn(ccx.tydesc_type)
 }
diff --git a/src/librustc/middle/trans/type_.rs b/src/librustc/middle/trans/type_.rs
index 34a150331091..764bdb026f47 100644
--- a/src/librustc/middle/trans/type_.rs
+++ b/src/librustc/middle/trans/type_.rs
@@ -189,18 +189,23 @@ impl Type {
             None => ()
         }
 
+        // Bit of a kludge: pick the fn typeref out of the tydesc..
         let ty = cx.tydesc_type.get_field(abi::tydesc_field_drop_glue);
         cx.tn.associate_type("glue_fn", &ty);
 
         return ty;
     }
 
+    pub fn glue_fn(tydesc: Type) -> Type {
+        let tydescpp = tydesc.ptr_to().ptr_to();
+        Type::func([ Type::nil().ptr_to(), tydescpp, Type::i8p() ],
+            &Type::void())
+    }
+
     pub fn tydesc(arch: Architecture) -> Type {
         let mut tydesc = Type::named_struct("tydesc");
-        let tydescpp = tydesc.ptr_to().ptr_to();
         let pvoid = Type::i8p();
-        let glue_fn_ty = Type::func([ Type::nil().ptr_to(), tydescpp, pvoid ],
-            &Type::void()).ptr_to();
+        let glue_fn_ty = Type::glue_fn(tydesc).ptr_to();
 
         let int_ty = Type::int(arch);
 
diff --git a/src/librustc/middle/typeck/check/mod.rs b/src/librustc/middle/typeck/check/mod.rs
index fa7959c7872b..4c074ce197ed 100644
--- a/src/librustc/middle/typeck/check/mod.rs
+++ b/src/librustc/middle/typeck/check/mod.rs
@@ -3506,8 +3506,14 @@ pub fn check_intrinsic_type(ccx: @mut CrateCtxt, it: @ast::foreign_item) {
             }
 
             "get_tydesc" => {
-              // FIXME (#3730): return *intrinsic::tydesc, not *()
-              (1u, ~[], ty::mk_nil_ptr(ccx.tcx))
+              let tydesc_name = special_idents::tydesc;
+              assert!(tcx.intrinsic_defs.contains_key(&tydesc_name));
+              let (_, tydesc_ty) = tcx.intrinsic_defs.get_copy(&tydesc_name);
+              let td_ptr = ty::mk_ptr(ccx.tcx, ty::mt {
+                  ty: tydesc_ty,
+                  mutbl: ast::m_imm
+              });
+              (1u, ~[], td_ptr)
             }
             "visit_tydesc" => {
               let tydesc_name = special_idents::tydesc;
diff --git a/src/libstd/unstable/intrinsics.rs b/src/libstd/unstable/intrinsics.rs
index c38b013a75aa..08fc90fa908c 100644
--- a/src/libstd/unstable/intrinsics.rs
+++ b/src/libstd/unstable/intrinsics.rs
@@ -209,6 +209,9 @@ pub extern "rust-intrinsic" {
     pub fn pref_align_of<T>() -> uint;
 
     /// Get a static pointer to a type descriptor.
+    #[cfg(not(stage0))]
+    pub fn get_tydesc<T>() -> *::intrinsic::TyDesc;
+    #[cfg(stage0)]
     pub fn get_tydesc<T>() -> *();
 
     /// Create a value initialized to zero.