diff --git a/chromeos_version.sh b/chromeos_version.sh
index 70c26912ef..df1fd9a60d 100755
--- a/chromeos_version.sh
+++ b/chromeos_version.sh
@@ -24,7 +24,7 @@ function export_release_version {
   # Increment by 2 in trunk after making a release branch.
   # Does not reset on a major/minor change (always increases).
   # (Trunk is always odd; branches are always even).
-  export CHROMEOS_VERSION_BRANCH=19
+  export CHROMEOS_VERSION_BRANCH=21
 
   # Patch number.
   # Increment by 1 each release on a branch.