diff --git a/docs/manifest-format.md b/docs/manifest-format.md
index 0d26296..bcdf5a8 100644
--- a/docs/manifest-format.md
+++ b/docs/manifest-format.md
@@ -105,6 +105,8 @@
   <!ATTLIST extend-project groups CDATA #IMPLIED>
   <!ATTLIST extend-project revision CDATA #IMPLIED>
   <!ATTLIST extend-project remote CDATA #IMPLIED>
+  <!ATTLIST extend-project dest-branch CDATA #IMPLIED>
+  <!ATTLIST extend-project upstream CDATA #IMPLIED>
 
   <!ELEMENT remove-project EMPTY>
   <!ATTLIST remove-project name  CDATA #REQUIRED>
@@ -423,6 +425,12 @@
 Attribute `remote`: If specified, overrides the remote of the original
 project.  Same syntax as the corresponding element of `project`.
 
+Attribute `dest-branch`: If specified, overrides the dest-branch of the original
+project.  Same syntax as the corresponding element of `project`.
+
+Attribute `upstream`: If specified, overrides the upstream of the original
+project.  Same syntax as the corresponding element of `project`.
+
 ### Element annotation
 
 Zero or more annotation elements may be specified as children of a
diff --git a/manifest_xml.py b/manifest_xml.py
index b7579d5..129eb3f 100644
--- a/manifest_xml.py
+++ b/manifest_xml.py
@@ -1289,6 +1289,8 @@
           remote = self._default.remote
         else:
           remote = self._get_remote(node)
+        dest_branch = node.getAttribute('dest-branch')
+        upstream = node.getAttribute('upstream')
 
         named_projects = self._projects[name]
         if dest_path and not path and len(named_projects) > 1:
@@ -1304,6 +1306,10 @@
 
           if remote_name:
             p.remote = remote.ToRemoteSpec(name)
+          if dest_branch:
+            p.dest_branch = dest_branch
+          if upstream:
+            p.upstream = upstream
 
           if dest_path:
             del self._paths[p.relpath]
diff --git a/tests/test_manifest_xml.py b/tests/test_manifest_xml.py
index 48403c0..e181b64 100644
--- a/tests/test_manifest_xml.py
+++ b/tests/test_manifest_xml.py
@@ -874,3 +874,27 @@
     else:
       self.assertEqual(manifest.projects[0].relpath, 'bar')
       self.assertEqual(manifest.projects[1].relpath, 'y')
+
+  def test_extend_project_dest_branch(self):
+    manifest = self.getXmlManifest("""
+<manifest>
+  <remote name="default-remote" fetch="http://localhost" />
+  <default remote="default-remote" revision="refs/heads/main" dest-branch="foo" />
+  <project name="myproject" />
+  <extend-project name="myproject" dest-branch="bar" />
+</manifest>
+""")
+    self.assertEqual(len(manifest.projects), 1)
+    self.assertEqual(manifest.projects[0].dest_branch, 'bar')
+
+  def test_extend_project_upstream(self):
+    manifest = self.getXmlManifest("""
+<manifest>
+  <remote name="default-remote" fetch="http://localhost" />
+  <default remote="default-remote" revision="refs/heads/main" />
+  <project name="myproject" />
+  <extend-project name="myproject" upstream="bar" />
+</manifest>
+""")
+    self.assertEqual(len(manifest.projects), 1)
+    self.assertEqual(manifest.projects[0].upstream, 'bar')