diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/BooleanItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/BooleanItem.php
index caf1d24..2c1f6ae 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/BooleanItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/BooleanItem.php
@@ -54,8 +54,6 @@ public static function schema(FieldDefinitionInterface $field_definition) {
         'value' => array(
           'type' => 'int',
           'size' => 'tiny',
-          'not null' => TRUE,
-          'default' => 0,
         ),
       ),
     );
diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/DateItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/DateItem.php
index 8c5a82c..1082af3 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/DateItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/DateItem.php
@@ -53,8 +53,8 @@ public static function schema(FieldDefinitionInterface $field_definition) {
       'columns' => array(
         'value' => array(
           'type' => 'int',
-          'not null' => TRUE,
-          'default' => 0,
+          // @todo Needs a size. What kind of value do we store here anyway, a
+          // timestamp?
         ),
       ),
     );
diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EmailItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EmailItem.php
index 514c160..64fbef0 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EmailItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EmailItem.php
@@ -54,7 +54,6 @@ public static function schema(FieldDefinitionInterface $field_definition) {
         'value' => array(
           'type' => 'varchar',
           'length' => EMAIL_MAX_LENGTH,
-          'not null' => FALSE,
         ),
       ),
     );
diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/FloatItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/FloatItem.php
index 27a6001..fef58b7 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/FloatItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/FloatItem.php
@@ -53,7 +53,6 @@ public static function schema(FieldDefinitionInterface $field_definition) {
       'columns' => array(
         'value' => array(
           'type' => 'float',
-          'not null' => FALSE,
         ),
       ),
     );
diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/IntegerItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/IntegerItem.php
index 1e084dc..23bb1ad 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/IntegerItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/IntegerItem.php
@@ -52,8 +52,6 @@ public static function schema(FieldDefinitionInterface $field_definition) {
       'columns' => array(
         'value' => array(
           'type' => 'int',
-          'not null' => TRUE,
-          'default' => 0,
         ),
       ),
     );
diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/LanguageItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/LanguageItem.php
index 89ce29d..ce4a008 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/LanguageItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/LanguageItem.php
@@ -67,8 +67,6 @@ public static function schema(FieldDefinitionInterface $field_definition) {
         'value' => array(
           'type' => 'varchar',
           'length' => 12,
-          'not null' => TRUE,
-          'default' => '',
         ),
       ),
     );
diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/StringItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/StringItem.php
index 43dfaf2..feb5bd7 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/StringItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/StringItem.php
@@ -56,7 +56,6 @@ public static function schema(FieldDefinitionInterface $field_definition) {
         'value' => array(
           'type' => 'varchar',
           'length' => $field_definition->getFieldSetting('max_length'),
-          'not null' => FALSE,
         ),
       ),
     );
diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/UriItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/UriItem.php
index d920b2d..79e5d8d 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/UriItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/UriItem.php
@@ -53,7 +53,6 @@ public static function schema(FieldDefinitionInterface $field_definition) {
       'columns' => array(
         'value' => array(
           'type' => 'text',
-          'not null' => FALSE,
         ),
       ),
     );