diff --git a/core/modules/config/tests/config_test/src/Entity/ConfigTest.php b/core/modules/config/tests/config_test/src/Entity/ConfigTest.php
index 1bd1d8dee9..c432c5bf2c 100644
--- a/core/modules/config/tests/config_test/src/Entity/ConfigTest.php
+++ b/core/modules/config/tests/config_test/src/Entity/ConfigTest.php
@@ -22,6 +22,7 @@
  *     },
  *     "access" = "Drupal\config_test\ConfigTestAccessControlHandler"
  *   },
+ *   rest_resource = TRUE,
  *   config_prefix = "dynamic",
  *   entity_keys = {
  *     "id" = "id",
diff --git a/core/modules/rest/src/Plugin/rest/resource/EntityResource.php b/core/modules/rest/src/Plugin/rest/resource/EntityResource.php
index 9111fafccc..8cf6cb236a 100644
--- a/core/modules/rest/src/Plugin/rest/resource/EntityResource.php
+++ b/core/modules/rest/src/Plugin/rest/resource/EntityResource.php
@@ -390,6 +390,20 @@ protected function getBaseRoute($canonical_path, $method) {
   }
 
   /**
+   * {@inheritdoc}
+   */
+  public function availableMethods() {
+    $methods = parent::availableMethods();
+    if ($this->isConfigEntityResource() && !empty($this->entityType->get('rest_resource'))) {
+      // Currently only GET is supported for Config Entities.
+      // @todo Remove when supported https://www.drupal.org/node/2300677
+      $unsupported_methods = ['POST', 'PUT', 'DELETE', 'PATCH'];
+      $methods = array_diff($methods, $unsupported_methods);
+    }
+    return $methods;
+  }
+
+  /**
    * Checks if this resource is for a Config Entity.
    *
    * @return bool