diff --git a/recipes/README.recipes.md b/recipes/README.recipes.md
index 14e691fb7..fcfb004d0 100644
--- a/recipes/README.recipes.md
+++ b/recipes/README.recipes.md
@@ -343,7 +343,7 @@ Returns:
 
 — **def [set\_change\_label](/recipes/recipe_modules/gerrit/api.py#248)(self, host, change, label_name, label_value, name=None, step_test_data=None):**
 
-— **def [update\_files](/recipes/recipe_modules/gerrit/api.py#290)(self, host, project, branch, new_contents_by_file_path, commit_msg, params=frozenset(['status=NEW']), submit=False):**
+— **def [update\_files](/recipes/recipe_modules/gerrit/api.py#290)(self, host, project, branch, new_contents_by_file_path, commit_msg, params=frozenset(['status=NEW']), submit=False, submit_later=False):**
 
 Update a set of files by creating and submitting a Gerrit CL.
 
@@ -357,6 +357,9 @@ Args:
   * params: A list of additional ChangeInput specifiers, with format
       'key=value'.
   * submit: Should land this CL instantly.
+  * submit_later: If this change has related CLs, we may want to commit
+       them in a chain. So only set Bot-Commit+1, making it ready for
+       submit together. Ignored if submit is True.
 
 Returns:
   A ChangeInfo dictionary as documented here:
diff --git a/recipes/recipe_modules/gerrit/api.py b/recipes/recipe_modules/gerrit/api.py
index be4dac2aa..38de53439 100644
--- a/recipes/recipe_modules/gerrit/api.py
+++ b/recipes/recipe_modules/gerrit/api.py
@@ -294,7 +294,8 @@ class GerritApi(recipe_api.RecipeApi):
                    new_contents_by_file_path,
                    commit_msg,
                    params=frozenset(['status=NEW']),
-                   submit=False):
+                   submit=False,
+                   submit_later=False):
     """Update a set of files by creating and submitting a Gerrit CL.
 
     Args:
@@ -307,6 +308,9 @@ class GerritApi(recipe_api.RecipeApi):
       * params: A list of additional ChangeInput specifiers, with format
           'key=value'.
       * submit: Should land this CL instantly.
+      * submit_later: If this change has related CLs, we may want to commit
+           them in a chain. So only set Bot-Commit+1, making it ready for
+           submit together. Ignored if submit is True.
 
     Returns:
       A ChangeInfo dictionary as documented here:
@@ -361,7 +365,7 @@ class GerritApi(recipe_api.RecipeApi):
         change,
     ])
 
-    if submit:
+    if submit or submit_later:
       self('set Bot-Commit+1 for change %d' % change, [
           'setbotcommit',
           '--host',
@@ -369,6 +373,7 @@ class GerritApi(recipe_api.RecipeApi):
           '--change',
           change,
       ])
+    if submit:
       submit_cmd = [
           'submitchange',
           '--host',