diff --git a/core/modules/migrate/src/Plugin/migrate/process/Concat.php b/core/modules/migrate/src/Plugin/migrate/process/Concat.php
index e3323b4..e394147 100644
--- a/core/modules/migrate/src/Plugin/migrate/process/Concat.php
+++ b/core/modules/migrate/src/Plugin/migrate/process/Concat.php
@@ -16,6 +16,8 @@
  * Available configuration keys:
  * - delimiter: (optional) A delimiter, or glue string, to insert between the
  *   strings.
+ * - exclude_empty: (optional) If set, empty values will be excluded from the
+ *   output. Defaults to FALSE.
  *
  * Examples:
  *
@@ -49,6 +51,38 @@
  * and "/" as the delimiter, if the 'foo' property is "wambooli" and the 'bar'
  * property is "pastafazoul", new_text_field will be "wambooli/pastafazoul".
  *
+ * You can also choose to exclude empty values from the output.
+ *
+ * @code
+ * process:
+ *   new_text_field:
+ *     plugin: concat
+ *     source:
+ *       - foo
+ *       - bar
+ *       - oof
+ *     delimiter: /
+ * @endcode
+ *
+ * For example, if the 'foo' property is "wambooli" and the 'bar' property is
+ * NULL and the 'oof' property is "pastafazoul", with a delimiter of "/",
+ * new_text_field will be "wambooli//pastafazoul".
+ *
+ * @code
+ * process:
+ *   new_text_field:
+ *     plugin: concat
+ *     source:
+ *       - foo
+ *       - bar
+ *       - oof
+ *     exclude_empty: TRUE
+ *     delimiter: /
+ * @endcode
+ *
+ * While, in the same case, but with exclude_empty set to TRUE, new_text_field
+ * will be "wambooli/pastafazoul".
+ *
  * @see \Drupal\migrate\Plugin\MigrateProcessInterface
  *
  * @MigrateProcessPlugin(
@@ -64,6 +98,9 @@ class Concat extends ProcessPluginBase {
   public function transform($value, MigrateExecutableInterface $migrate_executable, Row $row, $destination_property) {
     if (is_array($value)) {
       $delimiter = isset($this->configuration['delimiter']) ? $this->configuration['delimiter'] : '';
+      if (!empty($this->configuration['exclude_empty'])) {
+        $value = array_filter($value);
+      }
       return implode($delimiter, $value);
     }
     else {
diff --git a/core/modules/migrate/tests/src/Unit/process/ConcatTest.php b/core/modules/migrate/tests/src/Unit/process/ConcatTest.php
index ea93e46..cce1d71 100644
--- a/core/modules/migrate/tests/src/Unit/process/ConcatTest.php
+++ b/core/modules/migrate/tests/src/Unit/process/ConcatTest.php
@@ -1,10 +1,5 @@
 <?php
 
-/**
- * @file
- * Contains \Drupal\Tests\migrate\Unit\process\ConcatTest.
- */
-
 namespace Drupal\Tests\migrate\Unit\process;
 
 use Drupal\migrate\MigrateException;
@@ -18,52 +13,83 @@
 class ConcatTest extends MigrateProcessTestCase {
 
   /**
-   * {@inheritdoc}
+   * Test concat works without a delimiter.
+   *
+   * @dataProvider providerConcatWithoutDelimiter
    */
-  protected function setUp() {
-    $this->plugin = new TestConcat();
-    parent::setUp();
+  public function testConcatWithoutDelimiter($input, $expected, $configuration = []) {
+    $this->plugin = new Concat($configuration, '', []);
+    $value = $this->plugin->transform($input, $this->migrateExecutable, $this->row, 'destinationproperty');
+    $this->assertSame($expected, $value);
   }
 
   /**
-   * Test concat works without a delimiter.
+   * Data provider for testConcatWithoutDelimiter().
    */
-  public function testConcatWithoutDelimiter() {
-    $value = $this->plugin->transform(['foo', 'bar'], $this->migrateExecutable, $this->row, 'destinationproperty');
-    $this->assertSame($value, 'foobar');
+  public function providerConcatWithoutDelimiter() {
+    return [
+      'no configuration' => [['foo', 'bar'], 'foobar'],
+      'with delimiter' => [['foo', 'bar'], 'foo_bar', ['delimiter' => '_']],
+      'no delimiter, exclude_empty is true' => [
+        ['foo', NULL, 'bar'],
+        'foobar',
+        ['exclude_empty' => TRUE]
+      ],
+      'no delimiter, exclude_empty is false' => [
+        ['foo', NULL, 'bar'],
+        'foobar',
+        ['exclude_empty' => FALSE]
+      ],
+      'with delimiter, exclude_empty is true, NULL' => [
+        ['foo', NULL, 'bar'],
+        'foo_bar',
+        ['delimiter' => '_', 'exclude_empty' => TRUE]
+      ],
+      'with delimiter, exclude_empty is false, NULL' => [
+        ['foo', NULL, 'bar'],
+        'foo__bar',
+        ['delimiter' => '_', 'exclude_empty' => FALSE]
+      ],
+      'with delimiter, exclude_empty is not set, NULL' => [
+        ['foo', NULL, 'bar'],
+        'foo__bar',
+        ['delimiter' => '_']
+      ],
+      'with delimiter, exclude_empty is true, empty string' => [
+        ['foo', '', 'bar'],
+        'foo_bar',
+        ['delimiter' => '_', 'exclude_empty' => TRUE]
+      ],
+      'with delimiter, exclude_empty is false, empty string' => [
+        ['foo', '', 'bar'],
+        'foo__bar',
+        ['delimiter' => '_', 'exclude_empty' => FALSE]
+      ],
+      'with delimiter, exclude_empty is not set, empty string' => [
+        ['foo', '', 'bar'],
+        'foo__bar',
+        ['delimiter' => '_']
+      ],
+      'with delimiter, exclude_empty is true, zero' => [
+        ['foo', 0, 'bar'],
+        'foo_0_bar',
+        ['delimiter' => '_', 'exclude_empty' => TRUE]
+      ],
+      'with delimiter, exclude_empty is true, space' => [
+        ['foo', ' ', 'bar'],
+        'foo_ _bar',
+        ['delimiter' => '_', 'exclude_empty' => TRUE]
+      ],
+    ];
   }
 
   /**
    * Test concat fails properly on non-arrays.
    */
   public function testConcatWithNonArray() {
+    $this->plugin = new Concat([], '', []);
     $this->setExpectedException(MigrateException::class);
     $this->plugin->transform('foo', $this->migrateExecutable, $this->row, 'destinationproperty');
   }
 
-  /**
-   * Test concat works without a delimiter.
-   */
-  public function testConcatWithDelimiter() {
-    $this->plugin->setDelimiter('_');
-    $value = $this->plugin->transform(['foo', 'bar'], $this->migrateExecutable, $this->row, 'destinationproperty');
-    $this->assertSame($value, 'foo_bar');
-  }
-
-}
-
-class TestConcat extends Concat {
-  public function __construct() {
-  }
-
-  /**
-   * Set the delimiter.
-   *
-   * @param string $delimiter
-   *   The new delimiter.
-   */
-  public function setDelimiter($delimiter) {
-    $this->configuration['delimiter'] = $delimiter;
-  }
-
 }