diff --git a/core/modules/field_ui/src/Form/FieldStorageConfigEditForm.php b/core/modules/field_ui/src/Form/FieldStorageConfigEditForm.php
index 99c9ff6..8e8a0d8 100644
--- a/core/modules/field_ui/src/Form/FieldStorageConfigEditForm.php
+++ b/core/modules/field_ui/src/Form/FieldStorageConfigEditForm.php
@@ -118,7 +118,7 @@ public function form(array $form, FormStateInterface $form_state) {
          ':input[name="cardinality"]' => array('value' => 'number'),
         ),
         'disabled' => array(
-         ':input[name="cardinality"]' => array('value' => -1),
+         ':input[name="cardinality"]' => array('value' => FieldStorageDefinitionInterface::CARDINALITY_UNLIMITED),
         ),
       ),
     );
@@ -153,7 +153,7 @@ public function validate(array $form, FormStateInterface $form_state) {
    */
   public function buildEntity(array $form, FormStateInterface $form_state) {
     // Save field cardinality.
-    if ($form_state->getValue('cardinality') === 'number') {
+    if ($form_state->getValue('cardinality') === 'number' && $form_state->getValue('cardinality_number')) {
       $form_state->setValue('cardinality', $form_state->getValue('cardinality_number'));
     }