diff --git a/recipes/README.recipes.md b/recipes/README.recipes.md
index b091dc418..8bde607ad 100644
--- a/recipes/README.recipes.md
+++ b/recipes/README.recipes.md
@@ -53,7 +53,7 @@ Wrapper for easy calling of bot_update.
 Deapplies a patch, taking care of DEPS and solution revisions properly.
     
 
-— **def [ensure\_checkout](/recipes/recipe_modules/bot_update/api.py#68)(self, gclient_config=None, suffix=None, patch=True, update_presentation=True, patch_root=None, no_shallow=False, with_branch_heads=False, with_tags=False, refs=None, patch_oauth2=None, oauth2_json=None, use_site_config_creds=None, clobber=False, root_solution_revision=None, rietveld=None, issue=None, patchset=None, gerrit_no_reset=False, gerrit_no_rebase_patch_ref=False, disable_syntax_validation=False, manifest_name=None, \*\*kwargs):**
+— **def [ensure\_checkout](/recipes/recipe_modules/bot_update/api.py#68)(self, gclient_config=None, suffix=None, patch=True, update_presentation=True, patch_root=None, no_shallow=True, with_branch_heads=False, with_tags=False, refs=None, patch_oauth2=None, oauth2_json=None, use_site_config_creds=None, clobber=False, root_solution_revision=None, rietveld=None, issue=None, patchset=None, gerrit_no_reset=False, gerrit_no_rebase_patch_ref=False, disable_syntax_validation=False, manifest_name=None, \*\*kwargs):**
 
 Args:
   gclient_config: The gclient configuration to use when running bot_update.
diff --git a/recipes/recipe_modules/bot_update/api.py b/recipes/recipe_modules/bot_update/api.py
index 2e4e13e3b..ff55263a0 100644
--- a/recipes/recipe_modules/bot_update/api.py
+++ b/recipes/recipe_modules/bot_update/api.py
@@ -67,7 +67,7 @@ class BotUpdateApi(recipe_api.RecipeApi):
 
   def ensure_checkout(self, gclient_config=None, suffix=None,
                       patch=True, update_presentation=True,
-                      patch_root=None, no_shallow=False,
+                      patch_root=None, no_shallow=True,
                       with_branch_heads=False, with_tags=False, refs=None,
                       patch_oauth2=None, oauth2_json=None,
                       use_site_config_creds=None, clobber=False,
@@ -208,8 +208,8 @@ class BotUpdateApi(recipe_api.RecipeApi):
 
     if clobber:
       cmd.append('--clobber')
-    if no_shallow:
-      cmd.append('--no_shallow')
+    if no_shallow is False:
+      cmd.append('--maybe_shallow')
     if with_branch_heads or cfg.with_branch_heads:
       cmd.append('--with_branch_heads')
     if with_tags or cfg.with_tags:
diff --git a/recipes/recipe_modules/bot_update/examples/full.expected/no_shallow.json b/recipes/recipe_modules/bot_update/examples/full.expected/shallow.json
similarity index 99%
rename from recipes/recipe_modules/bot_update/examples/full.expected/no_shallow.json
rename to recipes/recipe_modules/bot_update/examples/full.expected/shallow.json
index 039848f94..9eba242af 100644
--- a/recipes/recipe_modules/bot_update/examples/full.expected/no_shallow.json
+++ b/recipes/recipe_modules/bot_update/examples/full.expected/shallow.json
@@ -18,7 +18,7 @@
       "/path/to/tmp/json",
       "--revision",
       "src@HEAD",
-      "--no_shallow",
+      "--maybe_shallow",
       "--disable-syntax-validation"
     ],
     "env_prefixes": {
diff --git a/recipes/recipe_modules/bot_update/examples/full.py b/recipes/recipe_modules/bot_update/examples/full.py
index 7413c5054..45a9ca255 100644
--- a/recipes/recipe_modules/bot_update/examples/full.py
+++ b/recipes/recipe_modules/bot_update/examples/full.py
@@ -40,7 +40,7 @@ def RunSteps(api):
 
   patch = api.properties.get('patch', True)
   clobber = True if api.properties.get('clobber') else False
-  no_shallow = True if api.properties.get('no_shallow') else False
+  no_shallow = True if api.properties.get('no_shallow', 1) else False
   with_branch_heads = api.properties.get('with_branch_heads', False)
   with_tags = api.properties.get('with_tags', False)
   refs = api.properties.get('refs', [])
@@ -148,8 +148,8 @@ def GenTests(api):
       rietveld='https://rietveld.example.com/',
       fail_patch='download'
   ) + api.step_data('bot_update', retcode=87)
-  yield api.test('no_shallow') + api.properties(
-      no_shallow=1
+  yield api.test('shallow') + api.properties(
+      no_shallow=0
   )
   yield api.test('clobber') + api.properties(
       clobber=1
diff --git a/recipes/recipe_modules/bot_update/resources/bot_update.py b/recipes/recipe_modules/bot_update/resources/bot_update.py
index a4fd22198..a51494ce3 100755
--- a/recipes/recipe_modules/bot_update/resources/bot_update.py
+++ b/recipes/recipe_modules/bot_update/resources/bot_update.py
@@ -1038,9 +1038,9 @@ def parse_args():
                    help='Delete checkout first, always')
   parse.add_option('--output_json',
                    help='Output JSON information into a specified file')
-  parse.add_option('--no_shallow', action='store_true',
-                   help='Bypass disk detection and never shallow clone. '
-                        'Does not override the --shallow flag')
+  parse.add_option('--maybe_shallow', action='store_true',
+                   help='Enables turning on shallow mode if total disk '
+                        'space is low.')
   parse.add_option('--refs', action='append',
                    help='Also fetch this refspec for the main solution(s). '
                         'Eg. +refs/branch-heads/*')
@@ -1126,7 +1126,7 @@ def prepare(options, git_slns, active):
                                            total_disk_space_gb,
                                            percent_used)
   shallow = (total_disk_space < SHALLOW_CLONE_THRESHOLD
-             and not options.no_shallow)
+             and options.maybe_shallow)
 
   # The first solution is where the primary DEPS file resides.
   first_sln = dir_names[0]