diff --git a/app/code/Magento/Catalog/Model/Product/Attribute/Backend/Boolean.php b/app/code/Magento/Catalog/Model/Product/Attribute/Backend/Boolean.php
index c2108b0273bdb..dbefb09f06bd1 100644
--- a/app/code/Magento/Catalog/Model/Product/Attribute/Backend/Boolean.php
+++ b/app/code/Magento/Catalog/Model/Product/Attribute/Backend/Boolean.php
@@ -25,7 +25,9 @@ public function beforeSave($object)
         $attributeCode = $this->getAttribute()->getName();
         if ($object->getData('use_config_' . $attributeCode)) {
             $object->setData($attributeCode, BooleanSource::VALUE_USE_CONFIG);
+            return $this;
         }
-        return $this;
+
+        return parent::beforeSave($object);
     }
 }
diff --git a/app/code/Magento/Downloadable/Setup/Patch/Data/InstallDownloadableAttributes.php b/app/code/Magento/Downloadable/Setup/Patch/Data/InstallDownloadableAttributes.php
index 9c101425e49ae..da1bf47f0f7f3 100644
--- a/app/code/Magento/Downloadable/Setup/Patch/Data/InstallDownloadableAttributes.php
+++ b/app/code/Magento/Downloadable/Setup/Patch/Data/InstallDownloadableAttributes.php
@@ -142,7 +142,7 @@ public function apply()
                 'visible' => false,
                 'required' => false,
                 'user_defined' => false,
-                'default' => '0',
+                'default' => null,
                 'searchable' => false,
                 'filterable' => false,
                 'comparable' => false,
diff --git a/app/code/Magento/Downloadable/etc/module.xml b/app/code/Magento/Downloadable/etc/module.xml
index 72aadff621eca..99c6e5e1cc49c 100644
--- a/app/code/Magento/Downloadable/etc/module.xml
+++ b/app/code/Magento/Downloadable/etc/module.xml
@@ -6,7 +6,7 @@
  */
 -->
 <config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Module/etc/module.xsd">
-    <module name="Magento_Downloadable" >
+    <module name="Magento_Downloadable">
         <sequence>
             <module name="Magento_Catalog"/>
         </sequence>
diff --git a/app/code/Magento/Eav/Model/Entity/Attribute/AbstractAttribute.php b/app/code/Magento/Eav/Model/Entity/Attribute/AbstractAttribute.php
index 29ead9ff810e5..b545092e62244 100644
--- a/app/code/Magento/Eav/Model/Entity/Attribute/AbstractAttribute.php
+++ b/app/code/Magento/Eav/Model/Entity/Attribute/AbstractAttribute.php
@@ -416,9 +416,7 @@ public function getIsVisibleOnFront()
     }
 
     /**
-     * Returns default value
-     *
-     * @return string|int|bool|float
+     * @return string|null
      * @codeCoverageIgnore
      */
     public function getDefaultValue()
diff --git a/app/code/Magento/Eav/Model/Entity/Attribute/Backend/AbstractBackend.php b/app/code/Magento/Eav/Model/Entity/Attribute/Backend/AbstractBackend.php
index 53c32e1cbfba4..14788bf15473e 100644
--- a/app/code/Magento/Eav/Model/Entity/Attribute/Backend/AbstractBackend.php
+++ b/app/code/Magento/Eav/Model/Entity/Attribute/Backend/AbstractBackend.php
@@ -204,12 +204,12 @@ public function getEntityValueId($entity)
     /**
      * Retrieve default value
      *
-     * @return mixed
+     * @return string
      */
     public function getDefaultValue()
     {
         if ($this->_defaultValue === null) {
-            if ($this->getAttribute()->getDefaultValue()) {
+            if ($this->getAttribute()->getDefaultValue() !== null) {
                 $this->_defaultValue = $this->getAttribute()->getDefaultValue();
             } else {
                 $this->_defaultValue = "";
@@ -285,7 +285,7 @@ public function afterLoad($object)
     public function beforeSave($object)
     {
         $attrCode = $this->getAttribute()->getAttributeCode();
-        if (!$object->hasData($attrCode) && $this->getDefaultValue()) {
+        if (!$object->hasData($attrCode) && $this->getDefaultValue() !== '') {
             $object->setData($attrCode, $this->getDefaultValue());
         }