diff --git a/src/comp/metadata/common.rs b/src/comp/metadata/common.rs
index 5393e1d0b7ed..58db989cba30 100644
--- a/src/comp/metadata/common.rs
+++ b/src/comp/metadata/common.rs
@@ -56,6 +56,12 @@ const uint tag_meta_item_word = 0x23u;
 
 const uint tag_meta_item_list = 0x24u;
 
+// The list of crates that this crate depends on
+const uint tag_crate_deps = 0x25u;
+
+// A single crate dependency
+const uint tag_crate_dep = 0x26u;
+
 // djb's cdb hashes.
 fn hash_node_id(&int node_id) -> uint { ret 177573u ^ (node_id as uint); }
 
diff --git a/src/comp/metadata/decoder.rs b/src/comp/metadata/decoder.rs
index 30d016b2cf17..8aab0e739fcf 100644
--- a/src/comp/metadata/decoder.rs
+++ b/src/comp/metadata/decoder.rs
@@ -327,7 +327,7 @@ fn list_meta_items(&ebml::doc meta_items, io::writer out) {
 }
 
 fn list_crate_attributes(&ebml::doc md, io::writer out) {
-    out.write_str("=Crate=");
+    out.write_str("=Crate Attributes=");
 
     for (ast::attribute attr in get_attributes(md)) {
         out.write_str(#fmt("%s", pprust::attribute_to_str(attr)));
@@ -340,6 +340,32 @@ fn get_crate_attributes(&vec[u8] data) -> ast::attribute[] {
     ret get_attributes(ebml::new_doc(data));
 }
 
+type crate_dep = tup(ast::crate_num, str);
+
+fn get_crate_deps(&vec[u8] data) -> vec[crate_dep] {
+    let vec[crate_dep] deps = [];
+    auto cratedoc = ebml::new_doc(data);
+    auto depsdoc = ebml::get_doc(cratedoc, tag_crate_deps);
+    auto crate_num = 1;
+    for each (ebml::doc depdoc in
+              ebml::tagged_docs(depsdoc, tag_crate_dep)) {
+        auto depname = str::unsafe_from_bytes(ebml::doc_data(depdoc));
+        deps += [tup(crate_num, depname)];
+        crate_num += 1;
+    }
+    ret deps;
+}
+
+fn list_crate_deps(&vec[u8] data, io::writer out) {
+    out.write_str("=External Dependencies=\n");
+
+    for (crate_dep dep in get_crate_deps(data)) {
+        out.write_str(#fmt("%d %s\n", dep._0, dep._1));
+    }
+
+    out.write_str("\n");
+}
+
 fn list_crate_items(vec[u8] bytes, &ebml::doc md, io::writer out) {
     out.write_str("=Items=\n");
     auto paths = ebml::get_doc(md, tag_paths);
@@ -364,6 +390,7 @@ fn list_crate_items(vec[u8] bytes, &ebml::doc md, io::writer out) {
 fn list_crate_metadata(vec[u8] bytes, io::writer out) {
     auto md = ebml::new_doc(bytes);
     list_crate_attributes(md, out);
+    list_crate_deps(bytes, out);
     list_crate_items(bytes, md, out);
 }
 
diff --git a/src/comp/metadata/encoder.rs b/src/comp/metadata/encoder.rs
index 53af9b00dbc1..89634d233bff 100644
--- a/src/comp/metadata/encoder.rs
+++ b/src/comp/metadata/encoder.rs
@@ -520,6 +520,49 @@ fn synthesize_crate_attrs(&@encode_ctxt ecx,
     ret attrs;
 }
 
+fn encode_crate_deps(&ebml::writer ebml_w, &cstore::cstore cstore) {
+
+    fn get_ordered_names(&cstore::cstore cstore) -> vec[str] {
+        type hashkv = @tup(crate_num, cstore::crate_metadata);
+        type numname = tup(crate_num, str);
+
+        // Pull the cnums and names out of cstore
+        let vec[mutable numname] pairs = [mutable];
+        for each (hashkv hashkv in cstore.metas.items()) {
+            pairs += [mutable tup(hashkv._0, hashkv._1.name)];
+        }
+
+        // Sort by cnum
+        fn lteq(&numname kv1, &numname kv2) -> bool { kv1._0 <= kv2._0 }
+        std::sort::quick_sort(lteq, pairs);
+
+        // Sanity-check the crate numbers
+        auto expected_cnum = 1;
+        for (numname n in pairs) {
+            assert n._0 == expected_cnum;
+            expected_cnum += 1;
+        }
+
+        // Return just the names
+        fn name(&numname kv) -> str { kv._1 }
+        // mutable -> immutable hack for vec::map
+        auto immpairs = vec::slice(pairs, 0u, vec::len(pairs));
+        ret vec::map(name, immpairs);
+    }
+
+    // We're just going to write a list of crate names, with the assumption
+    // that they are numbered 1 to n.
+    // FIXME: This is not nearly enough to support correct versioning
+    // but is enough to get transitive crate dependencies working.
+    ebml::start_tag(ebml_w, tag_crate_deps);
+    for (str cname in get_ordered_names(cstore)) {
+        ebml::start_tag(ebml_w, tag_crate_dep);
+        ebml_w.writer.write(str::bytes(cname));
+        ebml::end_tag(ebml_w);
+    }
+    ebml::end_tag(ebml_w);
+}
+
 fn encode_metadata(&@crate_ctxt cx, &@crate crate) -> str {
 
     auto abbrevs = map::mk_hashmap(ty::hash_ty, ty::eq_ty);
@@ -531,6 +574,9 @@ fn encode_metadata(&@crate_ctxt cx, &@crate crate) -> str {
 
     auto crate_attrs = synthesize_crate_attrs(ecx, crate);
     encode_attributes(ebml_w, crate_attrs);
+
+    encode_crate_deps(ebml_w, cx.sess.get_cstore());
+
     // Encode and index the paths.
 
     ebml::start_tag(ebml_w, tag_paths);