diff -u b/core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorage.php b/core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorage.php
--- b/core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorage.php
+++ b/core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorage.php
@@ -482,6 +482,7 @@
       return [];
     }
 
+    $storage_definitions = $this->entityManager->getFieldStorageDefinitions($this->entityTypeId);
     $values = [];
     foreach ($records as $id => $record) {
       $values[$id] = [];
@@ -493,12 +494,17 @@
         // that store several properties).
         if ($field_name = strstr($name, '__', TRUE)) {
           $property_name = substr($name, strpos($name, '__') + 2);
-          $values[$id][$field_name][LanguageInterface::LANGCODE_DEFAULT][$property_name] = $value;
+          $storage_definition = $storage_definitions[$field_name];
+          $definition_columns = $storage_definition->getColumns();
+          $values[$id][$field_name][LanguageInterface::LANGCODE_DEFAULT][$property_name] = !empty($definition_columns[$property_name]['serialize']) ? unserialize($value) : $value;
         }
         else {
           // Handle columns named directly after the field (e.g if the field
           // type only stores one property).
-          $values[$id][$name][LanguageInterface::LANGCODE_DEFAULT] = $value;
+          $storage_definition = $storage_definitions[$name];
+          $columns = $storage_definition->getColumns();
+          $column = reset($columns);
+          $values[$id][$name][LanguageInterface::LANGCODE_DEFAULT] = !empty($column['serialize']) ? unserialize($value) : $value;
         }
       }
     }
@@ -551,7 +557,6 @@
         $all_fields = $table_mapping->getFieldNames($this->dataTable);
       }
 
-      $storage_definitions = $this->entityManager->getFieldStorageDefinitions($this->entityTypeId);
       $result = $query->execute();
       foreach ($result as $row) {
         $id = $row[$record_key];
@@ -563,19 +568,14 @@
         $translations[$id][$langcode] = TRUE;
 
         foreach ($all_fields as $field_name) {
-          $storage_definition = $storage_definitions[$field_name];
-          $definition_columns = $storage_definition->getColumns();
           $columns = $table_mapping->getColumnNames($field_name);
           // Do not key single-column fields by property name.
           if (count($columns) == 1) {
-            $column_name = reset($columns);
-            $column_attributes = $definition_columns[key($columns)];
-            $values[$id][$field_name][$langcode] = (!empty($column_attributes['serialize'])) ? unserialize($row[$column_name]) : $row[$column_name];
+            $values[$id][$field_name][$langcode] = $row[reset($columns)];
           }
           else {
             foreach ($columns as $property_name => $column_name) {
-              $column_attributes = $definition_columns[$property_name];
-              $values[$id][$field_name][$langcode][$property_name] = (!empty($column_attributes['serialize'])) ? unserialize($row[$column_name]) : $row[$column_name];
+              $values[$id][$field_name][$langcode][$property_name] = $row[$column_name];
             }
           }
         }
@@ -590,6 +590,7 @@
         $all_fields = $table_mapping->getFieldNames($this->dataTable);
       }
 
+      $storage_definitions = $this->entityManager->getFieldStorageDefinitions($this->entityTypeId);
       $result = $query->execute();
       foreach ($result as $row) {
         $id = $row[$record_key];
@@ -601,14 +602,19 @@
         $translations[$id][$langcode] = TRUE;
 
         foreach ($all_fields as $field_name) {
+          $storage_definition = $storage_definitions[$field_name];
+          $definition_columns = $storage_definition->getColumns();
           $columns = $table_mapping->getColumnNames($field_name);
           // Do not key single-column fields by property name.
           if (count($columns) == 1) {
-            $values[$id][$field_name][$langcode] = $row[reset($columns)];
+            $column_name = reset($columns);
+            $column_attributes = $definition_columns[key($columns)];
+            $values[$id][$field_name][$langcode] = (!empty($column_attributes['serialize'])) ? unserialize($row[$column_name]) : $row[$column_name];
           }
           else {
             foreach ($columns as $property_name => $column_name) {
-              $values[$id][$field_name][$langcode][$property_name] = $row[$column_name];
+              $column_attributes = $definition_columns[$property_name];
+              $values[$id][$field_name][$langcode][$property_name] = (!empty($column_attributes['serialize'])) ? unserialize($row[$column_name]) : $row[$column_name];
             }
           }
         }