diff --git a/src/libstd/ebml.rs b/src/libstd/ebml.rs
index dc379cec21b5..cc3d080d30ec 100644
--- a/src/libstd/ebml.rs
+++ b/src/libstd/ebml.rs
@@ -379,6 +379,14 @@ pub mod reader {
             f()
         }
 
+        #[cfg(stage0)]
+        fn read_struct<T>(&self, name: &str, f: fn() -> T) -> T {
+            debug!("read_struct(name=%s)", name);
+            f()
+        }
+        #[cfg(stage1)]
+        #[cfg(stage2)]
+        #[cfg(stage3)]
         fn read_struct<T>(&self, name: &str, _len: uint, f: fn() -> T) -> T {
             debug!("read_struct(name=%s)", name);
             f()
@@ -658,6 +666,11 @@ pub mod writer {
         }
 
         fn emit_rec(&self, f: fn()) { f() }
+        #[cfg(stage0)]
+        fn emit_struct(&self, _name: &str, f: fn()) { f() }
+        #[cfg(stage1)]
+        #[cfg(stage2)]
+        #[cfg(stage3)]
         fn emit_struct(&self, _name: &str, _len: uint, f: fn()) { f() }
         fn emit_field(&self, name: &str, _idx: uint, f: fn()) {
             self._emit_label(name);
diff --git a/src/libstd/json.rs b/src/libstd/json.rs
index 0dea73981db5..83e98ac1ed16 100644
--- a/src/libstd/json.rs
+++ b/src/libstd/json.rs
@@ -157,6 +157,15 @@ pub impl Encoder: serialize::Encoder {
         f();
         self.wr.write_char('}');
     }
+    #[cfg(stage0)]
+    fn emit_struct(&self, _name: &str, f: fn()) {
+        self.wr.write_char('{');
+        f();
+        self.wr.write_char('}');
+    }
+    #[cfg(stage1)]
+    #[cfg(stage2)]
+    #[cfg(stage3)]
     fn emit_struct(&self, _name: &str, _len: uint, f: fn()) {
         self.wr.write_char('{');
         f();
@@ -270,6 +279,13 @@ pub impl PrettyEncoder: serialize::Encoder {
         self.indent -= 2;
         self.wr.write_char('}');
     }
+    #[cfg(stage0)]
+    fn emit_struct(&self, _name: &str, f: fn()) {
+        self.emit_rec(f)
+    }
+    #[cfg(stage1)]
+    #[cfg(stage2)]
+    #[cfg(stage3)]
     fn emit_struct(&self, _name: &str, _len: uint, f: fn()) {
         self.emit_rec(f)
     }
@@ -870,6 +886,16 @@ pub impl Decoder: serialize::Decoder {
         move value
     }
 
+    #[cfg(stage0)]
+    fn read_struct<T>(&self, _name: &str, f: fn() -> T) -> T {
+        debug!("read_struct()");
+        let value = f();
+        self.pop();
+        move value
+    }
+    #[cfg(stage1)]
+    #[cfg(stage2)]
+    #[cfg(stage3)]
     fn read_struct<T>(&self, _name: &str, _len: uint, f: fn() -> T) -> T {
         debug!("read_struct()");
         let value = f();
diff --git a/src/libstd/prettyprint.rs b/src/libstd/prettyprint.rs
index d07c29d624ce..f122031a81a4 100644
--- a/src/libstd/prettyprint.rs
+++ b/src/libstd/prettyprint.rs
@@ -162,6 +162,15 @@ pub impl Serializer: serialize::Encoder {
         self.wr.write_str(~"}");
     }
 
+    #[cfg(stage0)]
+    fn emit_struct(&self, name: &str, f: fn()) {
+        self.wr.write_str(fmt!("%s {", name));
+        f();
+        self.wr.write_str(~"}");
+    }
+    #[cfg(stage1)]
+    #[cfg(stage2)]
+    #[cfg(stage3)]
     fn emit_struct(&self, name: &str, _len: uint, f: fn()) {
         self.wr.write_str(fmt!("%s {", name));
         f();
diff --git a/src/libstd/serialize.rs b/src/libstd/serialize.rs
index 708df015dae4..da9bba1020c8 100644
--- a/src/libstd/serialize.rs
+++ b/src/libstd/serialize.rs
@@ -58,6 +58,11 @@ pub trait Encoder {
     fn emit_vec_elt(&self, idx: uint, f: fn());
 
     fn emit_rec(&self, f: fn());
+    #[cfg(stage0)]
+    fn emit_struct(&self, name: &str, f: fn());
+    #[cfg(stage1)]
+    #[cfg(stage2)]
+    #[cfg(stage3)]
     fn emit_struct(&self, name: &str, _len: uint, f: fn());
     fn emit_field(&self, f_name: &str, f_idx: uint, f: fn());
 
@@ -99,6 +104,11 @@ pub trait Decoder {
     fn read_vec_elt<T>(&self, idx: uint, f: fn() -> T) -> T;
 
     fn read_rec<T>(&self, f: fn() -> T) -> T;
+    #[cfg(stage0)]
+    fn read_struct<T>(&self, name: &str, f: fn() -> T) -> T;
+    #[cfg(stage1)]
+    #[cfg(stage2)]
+    #[cfg(stage3)]
     fn read_struct<T>(&self, name: &str, _len: uint, f: fn() -> T) -> T;
     fn read_field<T>(&self, name: &str, idx: uint, f: fn() -> T) -> T;