diff --git a/src/libstd/cleanup.rs b/src/libstd/cleanup.rs
index 2ea10b09c8ec1c6b25a41d19a8d7a76028ea568e..da24fef157858c12e9de9ca5a96a78a276ced0a7 100644
--- a/src/libstd/cleanup.rs
+++ b/src/libstd/cleanup.rs
@@ -13,7 +13,6 @@
 use libc::c_void;
 use ptr::{mut_null};
 use repr::BoxRepr;
-use cast::transmute;
 use unstable::intrinsics::TyDesc;
 
 type DropGlue<'self> = &'self fn(**TyDesc, *c_void);
@@ -40,18 +39,17 @@ unsafe fn each_live_alloc(read_next_before: bool,
     let box = local_heap::live_allocs();
     let mut box: *mut BoxRepr = transmute(box);
     while box != mut_null() {
-        let next_before = transmute((*box).header.next);
-        let uniq =
-            (*box).header.ref_count == managed::raw::RC_MANAGED_UNIQUE;
+        let next_before = (*box).next;
+        let uniq = (*box).ref_count == managed::RC_MANAGED_UNIQUE;
 
-        if !f(box, uniq) {
+        if !f(box as *mut raw::Box<()>, uniq) {
             return false;
         }
 
         if read_next_before {
             box = next_before;
         } else {
-            box = transmute((*box).header.next);
+            box = (*box).next;
         }
     }
     return true;
@@ -113,9 +111,9 @@ pub unsafe fn annihilate() {
     // callback, as the original value may have been freed.
     for each_live_alloc(false) |box, uniq| {
         if !uniq {
-            let tydesc: *TyDesc = transmute((*box).header.type_desc);
-            let data = transmute(&(*box).data);
-            ((*tydesc).drop_glue)(data);
+            let tydesc = (*box).type_desc;
+            let data = &(*box).data as *();
+            ((*tydesc).drop_glue)(data as *i8);
         }
     }
 
@@ -130,7 +128,7 @@ pub unsafe fn annihilate() {
             stats.n_bytes_freed +=
                 (*((*box).header.type_desc)).size
                 + sys::size_of::<BoxRepr>();
-            local_free(transmute(box));
+            local_free(box as *u8);
         }
     }
 
diff --git a/src/libstd/gc.rs b/src/libstd/gc.rs
index 911fb5625e58864d52b15e49e23c14d82944a11a..4feec26a2d982e4b923df0b67a46e95a530baee1 100644
--- a/src/libstd/gc.rs
+++ b/src/libstd/gc.rs
@@ -74,14 +74,14 @@ pub mod rustrt {
 }
 
 unsafe fn bump<T, U>(ptr: *T, count: uint) -> *U {
-    return cast::transmute(ptr::offset(ptr, count));
+    return ptr::offset(ptr, count) as *U;
 }
 
 unsafe fn align_to_pointer<T>(ptr: *T) -> *T {
     let align = sys::min_align_of::<*T>();
-    let ptr: uint = cast::transmute(ptr);
+    let ptr = ptr as uint;
     let ptr = (ptr + (align - 1)) & -align;
-    return cast::transmute(ptr);
+    return ptr as *T;
 }
 
 unsafe fn get_safe_point_count() -> uint {
@@ -126,8 +126,8 @@ unsafe fn is_safe_point(pc: *Word) -> Option<SafePoint> {
 // Walks the list of roots for the given safe point, and calls visitor
 // on each root.
 unsafe fn _walk_safe_point(fp: *Word, sp: SafePoint, visitor: Visitor) -> bool {
-    let fp_bytes: *u8 = cast::transmute(fp);
-    let sp_meta: *u32 = cast::transmute(sp.sp_meta);
+    let fp_bytes = fp as *u8;
+    let sp_meta = sp.sp_meta as *u32;
 
     let num_stack_roots = *sp_meta as uint;
     let num_reg_roots = *ptr::offset(sp_meta, 1) as uint;
@@ -173,9 +173,9 @@ unsafe fn walk_safe_point(fp: *Word, sp: SafePoint, visitor: Visitor) -> bool {
 
 // Is fp contained in segment?
 unsafe fn is_frame_in_segment(fp: *Word, segment: *StackSegment) -> bool {
-    let begin: Word = cast::transmute(segment);
-    let end: Word = cast::transmute((*segment).end);
-    let frame: Word = cast::transmute(fp);
+    let begin = segment as Word;
+    let end = (*segment).end as Word;
+    let frame = fp as Word;
 
     return begin <= frame && frame <= end;
 }