diff --git a/core/modules/layout_builder/layout_builder.install b/core/modules/layout_builder/layout_builder.install
index ec16a05537..7c1cae67ad 100644
--- a/core/modules/layout_builder/layout_builder.install
+++ b/core/modules/layout_builder/layout_builder.install
@@ -136,3 +136,27 @@ function layout_builder_update_8602() {
   ];
   Database::getConnection()->schema()->createTable('inline_block_usage', $inline_block_usage);
 }
+
+/**
+ * Increase the size of the section column of the *__layout_builder__layout
+ * table.
+ */
+function layout_builder_update_8603() {
+  $database = \Drupal::database();
+  $entity_types = \Drupal::entityTypeManager()->getDefinitions();
+  foreach ($entity_types as $entity_type => $type) {
+    if ($database->schema()
+      ->tableExists($entity_type . '__layout_builder__layout')) {
+      $database->query('ALTER TABLE ' . $entity_type . '__layout_builder__layout MODIFY layout_builder__layout_section LONGBLOB;');
+      $database->query('ALTER TABLE ' . $entity_type . '_revision__layout_builder__layout MODIFY layout_builder__layout_section LONGBLOB;');
+
+      $field = $entity_type . '.field_schema_data.layout_builder__layout';
+      $schema = \Drupal::keyValue('entity.storage_schema.sql');
+      $field_schema = $schema->get($field);
+      $field_schema[$entity_type . '__layout_builder__layout']['fields']['layout_builder__layout_section']['size'] = 'big';
+      $field_schema[$entity_type . '_revision__layout_builder__layout']['fields']['layout_builder__layout_section']['size'] = 'big';
+      $schema->set($field, $field_schema);
+    }
+  }
+}
+
diff --git a/core/modules/layout_builder/src/Plugin/Field/FieldType/LayoutSectionItem.php b/core/modules/layout_builder/src/Plugin/Field/FieldType/LayoutSectionItem.php
index 0865f0c7c5..4e3245a700 100644
--- a/core/modules/layout_builder/src/Plugin/Field/FieldType/LayoutSectionItem.php
+++ b/core/modules/layout_builder/src/Plugin/Field/FieldType/LayoutSectionItem.php
@@ -66,7 +66,7 @@ public static function schema(FieldStorageDefinitionInterface $field_definition)
       'columns' => [
         'section' => [
           'type' => 'blob',
-          'size' => 'normal',
+          'size' => 'big',
           'serialize' => TRUE,
         ],
       ],