diff --git a/core/lib/Drupal/Core/Config/FileStorage.php b/core/lib/Drupal/Core/Config/FileStorage.php
index 98316c3..b52552f 100644
--- a/core/lib/Drupal/Core/Config/FileStorage.php
+++ b/core/lib/Drupal/Core/Config/FileStorage.php
@@ -141,6 +141,9 @@ class FileStorage implements StorageInterface {
   protected function getDumper() {
     if (!isset($this->dumper)) {
       $this->dumper = new Dumper();
+      // Set Yaml\Dumper's default indentation for nested nodes/collections to
+      // 2 spaces for consistency with Drupal coding standards.
+      $this->dumper->setIndentation(2);
     }
     return $this->dumper;
   }
diff --git a/core/modules/aggregator/config/aggregator.settings.yml b/core/modules/aggregator/config/aggregator.settings.yml
index 8db22de..dfc0aa9 100644
--- a/core/modules/aggregator/config/aggregator.settings.yml
+++ b/core/modules/aggregator/config/aggregator.settings.yml
@@ -1,11 +1,11 @@
 fetcher: aggregator
 parser: aggregator
 processors:
-    - aggregator
+  - aggregator
 items:
-    allowed_html: '<a> <b> <br> <dd> <dl> <dt> <em> <i> <li> <ol> <p> <strong> <u> <ul>'
-    teaser_length: '600'
-    expire: '9676800'
+  allowed_html: '<a> <b> <br> <dd> <dl> <dt> <em> <i> <li> <ol> <p> <strong> <u> <ul>'
+  teaser_length: '600'
+  expire: '9676800'
 source:
-    list_max: '3'
-    category_selector: checkboxes
+  list_max: '3'
+  category_selector: checkboxes
diff --git a/core/modules/book/config/book.settings.yml b/core/modules/book/config/book.settings.yml
index 8763c7f..b61c415 100644
--- a/core/modules/book/config/book.settings.yml
+++ b/core/modules/book/config/book.settings.yml
@@ -1,6 +1,6 @@
 allowed_types:
-    - book
+  - book
 block:
-    navigation:
-        mode: all pages
+  navigation:
+    mode: all pages
 child_type: book
diff --git a/core/modules/contact/config/contact.settings.yml b/core/modules/contact/config/contact.settings.yml
index b23538a..413ebbc 100644
--- a/core/modules/contact/config/contact.settings.yml
+++ b/core/modules/contact/config/contact.settings.yml
@@ -1,4 +1,4 @@
 flood:
-    limit: '5'
-    interval: '3600'
+  limit: '5'
+  interval: '3600'
 user_default_enabled: '1'
diff --git a/core/modules/forum/config/forum.settings.yml b/core/modules/forum/config/forum.settings.yml
index bd39d97..97c9c34 100644
--- a/core/modules/forum/config/forum.settings.yml
+++ b/core/modules/forum/config/forum.settings.yml
@@ -1,11 +1,11 @@
 block:
-    active:
-        limit: '5'
-    new:
-        limit: '5'
+  active:
+    limit: '5'
+  new:
+    limit: '5'
 containers: []
 topics:
-    hot_threshold: '15'
-    order: '1'
-    page_limit: '25'
+  hot_threshold: '15'
+  order: '1'
+  page_limit: '25'
 vocabulary: '0'
diff --git a/core/modules/image/config/image.style.large.yml b/core/modules/image/config/image.style.large.yml
index d5602bf..3a1260d 100644
--- a/core/modules/image/config/image.style.large.yml
+++ b/core/modules/image/config/image.style.large.yml
@@ -1,10 +1,10 @@
 name: large
 effects:
-    ddd73aa7-4bd6-4c85-b600-bdf2b1628d1d:
-        name: image_scale
-        data:
-            width: '480'
-            height: '480'
-            upscale: '1'
-        weight: '0'
-        ieid: ddd73aa7-4bd6-4c85-b600-bdf2b1628d1d
+  ddd73aa7-4bd6-4c85-b600-bdf2b1628d1d:
+    name: image_scale
+    data:
+      width: '480'
+      height: '480'
+      upscale: '1'
+    weight: '0'
+    ieid: ddd73aa7-4bd6-4c85-b600-bdf2b1628d1d
diff --git a/core/modules/image/config/image.style.medium.yml b/core/modules/image/config/image.style.medium.yml
index a0b2d78..3f2b445 100644
--- a/core/modules/image/config/image.style.medium.yml
+++ b/core/modules/image/config/image.style.medium.yml
@@ -1,10 +1,10 @@
 name: medium
 effects:
-    bddf0d06-42f9-4c75-a700-a33cafa25ea0:
-        name: image_scale
-        data:
-            width: '220'
-            height: '220'
-            upscale: '1'
-        weight: '0'
-        ieid: bddf0d06-42f9-4c75-a700-a33cafa25ea0
+  bddf0d06-42f9-4c75-a700-a33cafa25ea0:
+    name: image_scale
+    data:
+      width: '220'
+      height: '220'
+      upscale: '1'
+    weight: '0'
+    ieid: bddf0d06-42f9-4c75-a700-a33cafa25ea0
diff --git a/core/modules/image/config/image.style.thumbnail.yml b/core/modules/image/config/image.style.thumbnail.yml
index f4cf3b5..83e6730 100644
--- a/core/modules/image/config/image.style.thumbnail.yml
+++ b/core/modules/image/config/image.style.thumbnail.yml
@@ -1,10 +1,10 @@
 name: thumbnail
 effects:
-    1cfec298-8620-4749-b100-ccb6c4500779:
-        name: image_scale
-        data:
-            width: '100'
-            height: '100'
-            upscale: '1'
-        weight: '0'
-        ieid: 1cfec298-8620-4749-b100-ccb6c4500779
+  1cfec298-8620-4749-b100-ccb6c4500779:
+    name: image_scale
+    data:
+      width: '100'
+      height: '100'
+      upscale: '1'
+    weight: '0'
+    ieid: 1cfec298-8620-4749-b100-ccb6c4500779
diff --git a/core/modules/search/config/search.settings.yml b/core/modules/search/config/search.settings.yml
index 97732b5..a1a88b4 100644
--- a/core/modules/search/config/search.settings.yml
+++ b/core/modules/search/config/search.settings.yml
@@ -1,22 +1,22 @@
 active_modules:
-    - node
-    - user
+  - node
+  - user
 and_or_limit: '7'
 default_module: node
 index:
-    cron_limit: '100'
-    overlap_cjk: '1'
-    minimum_word_size: '3'
-    tag_weights:
-        h1: '25'
-        h2: '18'
-        h3: '15'
-        h4: '14'
-        h5: '9'
-        h6: '6'
-        u: '3'
-        b: '3'
-        i: '3'
-        strong: '3'
-        em: '3'
-        a: '10'
+  cron_limit: '100'
+  overlap_cjk: '1'
+  minimum_word_size: '3'
+  tag_weights:
+    h1: '25'
+    h2: '18'
+    h3: '15'
+    h4: '14'
+    h5: '9'
+    h6: '6'
+    u: '3'
+    b: '3'
+    i: '3'
+    strong: '3'
+    em: '3'
+    a: '10'
diff --git a/core/modules/statistics/config/statistics.settings.yml b/core/modules/statistics/config/statistics.settings.yml
index 2b30aa6..e38a319 100644
--- a/core/modules/statistics/config/statistics.settings.yml
+++ b/core/modules/statistics/config/statistics.settings.yml
@@ -1,9 +1,9 @@
 access_log:
-    enabled: '0'
-    max_lifetime: '259200'
+  enabled: '0'
+  max_lifetime: '259200'
 count_content_views: '0'
 block:
-    popular:
-        top_day_limit: '0'
-        top_all_limit: '0'
-        top_recent_limit: '0'
+  popular:
+    top_day_limit: '0'
+    top_all_limit: '0'
+    top_recent_limit: '0'
diff --git a/core/modules/system/config/system.cron.yml b/core/modules/system/config/system.cron.yml
index 4d96e30..b9a5096 100644
--- a/core/modules/system/config/system.cron.yml
+++ b/core/modules/system/config/system.cron.yml
@@ -1,5 +1,5 @@
 key: ''
 threshold:
-    autorun: '10800'
-    requirements_warning: '172800'
-    requirements_error: '1209600'
+  autorun: '10800'
+  requirements_warning: '172800'
+  requirements_error: '1209600'
diff --git a/core/modules/system/config/system.performance.yml b/core/modules/system/config/system.performance.yml
index f73c09f..1eeb22a 100644
--- a/core/modules/system/config/system.performance.yml
+++ b/core/modules/system/config/system.performance.yml
@@ -1,9 +1,9 @@
 cache:
-    page:
-        enabled: '0'
-        max_age: '0'
+  page:
+    enabled: '0'
+    max_age: '0'
 preprocess:
-    css: '0'
-    js: '0'
+  css: '0'
+  js: '0'
 response:
-    gzip: '0'
+  gzip: '0'
diff --git a/core/modules/system/config/system.rss.yml b/core/modules/system/config/system.rss.yml
index 74b3228..6efa3bd 100644
--- a/core/modules/system/config/system.rss.yml
+++ b/core/modules/system/config/system.rss.yml
@@ -1,5 +1,5 @@
 channel:
-    description: ''
+  description: ''
 items:
-    limit: '10'
-    view_mode: fulltext
+  limit: '10'
+  view_mode: fulltext
diff --git a/core/modules/system/config/system.site.yml b/core/modules/system/config/system.site.yml
index 080d6b9..010dedf 100644
--- a/core/modules/system/config/system.site.yml
+++ b/core/modules/system/config/system.site.yml
@@ -2,6 +2,6 @@ name: Drupal
 mail: ''
 slogan: ''
 page:
-    403: ''
-    404: ''
-    front: user
+  403: ''
+  404: ''
+  front: user
diff --git a/core/modules/system/tests/modules/config_upgrade/config/config_upgrade.test.yml b/core/modules/system/tests/modules/config_upgrade/config/config_upgrade.test.yml
index 3957538..c921534 100644
--- a/core/modules/system/tests/modules/config_upgrade/config/config_upgrade.test.yml
+++ b/core/modules/system/tests/modules/config_upgrade/config/config_upgrade.test.yml
@@ -1,4 +1,4 @@
 parent:
-    bar: Bar
-    baz: Baz
+  bar: Bar
+  baz: Baz
 foo: Foo
diff --git a/core/modules/update/config/update.settings.yml b/core/modules/update/config/update.settings.yml
index 1caf745..da864d9 100644
--- a/core/modules/update/config/update.settings.yml
+++ b/core/modules/update/config/update.settings.yml
@@ -1,10 +1,10 @@
 check:
-    disabled_extensions: '0'
-    interval_days: '1'
+  disabled_extensions: '0'
+  interval_days: '1'
 fetch:
-    url: ''
-    max_attempts: '2'
-    timeout: '5'
+  url: ''
+  max_attempts: '2'
+  timeout: '5'
 notification:
-    emails: []
-    threshold: '0'
+  emails: []
+  threshold: '0'
diff --git a/core/modules/user/config/user.settings.yml b/core/modules/user/config/user.settings.yml
index 528395f..98c8d25 100644
--- a/core/modules/user/config/user.settings.yml
+++ b/core/modules/user/config/user.settings.yml
@@ -2,13 +2,13 @@ admin_role: ''
 anonymous: Anonymous
 verify_mail: '1'
 notify:
-    cancel_confirm: '1'
-    password_reset: '1'
-    status_activated: '1'
-    status_blocked: '0'
-    status_cancelled: '0'
-    register_admin_created: '1'
-    register_no_approval_required: '1'
-    register_pending_approval: '1'
+  cancel_confirm: '1'
+  password_reset: '1'
+  status_activated: '1'
+  status_blocked: '0'
+  status_cancelled: '0'
+  register_admin_created: '1'
+  register_no_approval_required: '1'
+  register_pending_approval: '1'
 register: visitors
 signatures: '0'