diff --git a/core/modules/migrate/src/Plugin/migrate/source/SqlBase.php b/core/modules/migrate/src/Plugin/migrate/source/SqlBase.php
index a730266e1d..a1777f6d1c 100644
--- a/core/modules/migrate/src/Plugin/migrate/source/SqlBase.php
+++ b/core/modules/migrate/src/Plugin/migrate/source/SqlBase.php
@@ -29,11 +29,20 @@
  *   joined. Using expressions in the query may result in column aliases in the
  *   JOIN clause which would be invalid SQL. If you run into this, set
  *   ignore_map to TRUE.
- * - conditions: (optional) Conditons that should be included in the query. This
+ * - conditions: (optional) Conditions that should be included in the query. This
  *   should be in array format with each array item providing values for field,
  *   value (optional) and operator (optional). Defaults to an empty array. If
  *   value is not defined, defaults to NULL. If operator is not defined, defaults
  *   to '='.
+ *   Example:
+ *   @code
+ *   source:
+ *     conditions:
+ *       -
+ *         field: type
+ *         value: article
+ *         operator: <>
+ *   @endcode
  *
  * For other optional configuration keys inherited from the parent class, refer
  * to \Drupal\migrate\Plugin\migrate\source\SourcePluginBase.
@@ -113,6 +122,18 @@
   public function __construct(array $configuration, $plugin_id, $plugin_definition, MigrationInterface $migration, StateInterface $state) {
     parent::__construct($configuration, $plugin_id, $plugin_definition, $migration);
     $this->state = $state;
+
+    // Verify conditions configuration.
+    if (isset($this->configuration['conditions'])) {
+      if (!is_array($this->configuration['conditions'])) {
+        throw new \InvalidArgumentException('Source "conditions" should be an array of conditions including field, value (optional), and operator (optional) values.');
+      }
+      foreach ($this->configuration['conditions'] as $condition) {
+        if (!is_array($condition) || !isset($condition['field'])) {
+          throw new \InvalidArgumentException('Source condition must be an array including field, value (optional), and operator (optional) values.');
+        }
+      }
+    }
   }
 
   /**
@@ -460,7 +481,7 @@ protected function mapJoinable() {
     if ($id_map_database_options['driver'] === 'pgsql' &&
       $source_database_options['driver'] === 'pgsql' &&
       $id_map_database_options['database'] != $source_database_options['database']
-      ) {
+    ) {
       return FALSE;
     }
 
diff --git a/core/modules/migrate/tests/src/Unit/SqlBaseTest.php b/core/modules/migrate/tests/src/Unit/SqlBaseTest.php
index bc2843e1e2..61433534d2 100644
--- a/core/modules/migrate/tests/src/Unit/SqlBaseTest.php
+++ b/core/modules/migrate/tests/src/Unit/SqlBaseTest.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\Tests\migrate\Unit;
 
+use Drupal\Core\State\StateInterface;
 use Drupal\migrate\Plugin\MigrationInterface;
 use Drupal\migrate\Plugin\migrate\source\SqlBase;
 use Drupal\Tests\UnitTestCase;
@@ -18,6 +19,82 @@
  */
 class SqlBaseTest extends UnitTestCase {
 
+  /**
+   * The default configuration array.
+   *
+   * @var array
+   */
+  protected $configuration = [];
+
+  /**
+   * The default plugin_id string.
+   *
+   * @var string
+   */
+  protected $pluginId = '';
+
+  /**
+   * The default plugin_definition array.
+   *
+   * @var array
+   */
+  protected $pluginDefinition = [];
+
+  /**
+   * Tests that source conditions are recognized.
+   *
+   * @param bool $expected_result
+   *   The expected result.
+   * @param array $conditions
+   *   An array of source conditions. Defaults to an empty array.
+   *
+   * @dataProvider sqlBaseConstructorTestProvider
+   */
+  public function testConstructor($expected_result, $conditions = []) {
+    $configuration = [
+      'conditions' => $conditions,
+    ];
+    // Setup the migration interface.
+    $migration = $this->getMockBuilder('Drupal\migrate\Plugin\MigrationInterface')
+      ->disableOriginalConstructor()
+      ->getMock();
+
+    // Setup the state object.
+    $state = $this->getMockBuilder('Drupal\Core\State\State')
+      ->disableOriginalConstructor()
+      ->getMock();
+
+    // Test with an invalid process pipeline.
+    $this->expectException(\InvalidArgumentException::class);
+    $sql_base = new TestSqlBase($configuration, $this->pluginId, $this->pluginDefinition, $migration, $state);
+  }
+
+  /**
+   * The data provider for testConstructor.
+   *
+   * @return array
+   *   An array of data per test run.
+   */
+  public function sqlBaseConstructorTestProvider() {
+    return [
+      // Source conditions is not an array.
+      [
+        TRUE,
+        '',
+      ],
+      // Source conditions is not a multidimensional array.
+      [
+        TRUE,
+        [''],
+      ],
+      // Source conditions condition does not specify 'field'.
+      [
+        TRUE,
+        [['']],
+      ],
+    ];
+  }
+
   /**
    * Tests that the ID map is joinable.
    *
@@ -61,6 +138,11 @@ public function testMapJoinable($expected_result, $id_map_is_sql, $with_id_map,
       ->method('getDatabase')
       ->willReturn($idmap_connection);
 
+    // Setup the State object.
+    $state = $this->getMockBuilder('Drupal\Core\State\State')
+      ->disableOriginalConstructor()
+      ->getMock();
+
     // Setup a migration entity.
     $migration = $this->createMock(MigrationInterface::class);
     $migration->expects($with_id_map ? $this->once() : $this->never())
@@ -68,7 +150,7 @@ public function testMapJoinable($expected_result, $id_map_is_sql, $with_id_map,
       ->willReturn($id_map_is_sql ? $sql : NULL);
 
     // Create our SqlBase test class.
-    $sql_base = new TestSqlBase();
+    $sql_base = new TestSqlBase($this->configuration, $this->pluginId, $this->pluginDefinition, $migration, $state);
     $sql_base->setMigration($migration);
     $sql_base->setDatabase($source_connection);
 
@@ -162,9 +244,12 @@ class TestSqlBase extends SqlBase {
   protected $ids;
 
   /**
-   * Override the constructor so we can create one easily.
+   * {@inheritdoc}
    */
-  public function __construct() {}
+  public function __construct(array $configuration, $plugin_id, $plugin_definition, MigrationInterface $migration, StateInterface $state) {
+    parent::__construct($configuration, $plugin_id, $plugin_definition, $migration, $state);
+    return TRUE;
+  }
 
   /**
    * Allows us to set the database during tests.