diff --git a/core/modules/node/src/NodeTypeForm.php b/core/modules/node/src/NodeTypeForm.php
index 03ae107..c3addc5 100644
--- a/core/modules/node/src/NodeTypeForm.php
+++ b/core/modules/node/src/NodeTypeForm.php
@@ -220,7 +220,7 @@ public function validateForm(array &$form, FormStateInterface $form_state) {
     if ($original_type && isset($disallowed_names[$original_type])) {
       unset($disallowed_names[$original_type]);
     }
-    if (in_array($name, $disallowed_names)) {
+    if (preg_grep('/^' . $name . '$/i', $disallowed_names)) {
       $form_state->setErrorByName('name', $this->t('The human-readable name %name is already taken.', array('%name' => $name)));
     }
   }
diff --git a/core/modules/node/src/Tests/NodeTypeTest.php b/core/modules/node/src/Tests/NodeTypeTest.php
index 9337b54..a23ebd2 100644
--- a/core/modules/node/src/Tests/NodeTypeTest.php
+++ b/core/modules/node/src/Tests/NodeTypeTest.php
@@ -93,6 +93,11 @@ public function testNodeTypeUnique() {
     $this->drupalPostForm('admin/structure/types/add', $edit, t('Save and manage fields'));
     $this->assertText(t('The human-readable name foo is already taken.'));
 
+    // Attempt to create a content type with the same name (case insensitive).
+    $edit['name'] = 'Foo';
+    $this->drupalPostForm('admin/structure/types/add', $edit, t('Save and manage fields'));
+    $this->assertText(t('The human-readable name Foo is already taken.'));
+
     // Attempt to create a content type with a different name.
     $edit['name'] = 'foo_2';
     $this->drupalPostForm('admin/structure/types/add', $edit, t('Save and manage fields'));