diff --git a/core/modules/migrate/src/Plugin/migrate/process/ArrayMap.php b/core/modules/migrate/src/Plugin/migrate/process/ArrayMap.php
index 022d09b..da06bee 100644
--- a/core/modules/migrate/src/Plugin/migrate/process/ArrayMap.php
+++ b/core/modules/migrate/src/Plugin/migrate/process/ArrayMap.php
@@ -2,6 +2,7 @@
 
 namespace Drupal\migrate\Plugin\migrate\process;
 
+use Drupal\migrate\MigrateException;
 use Drupal\migrate\MigrateExecutableInterface;
 use Drupal\migrate\ProcessPluginBase;
 use Drupal\migrate\Row;
@@ -23,6 +24,21 @@ public function transform($value, MigrateExecutableInterface $migrate_executable
     $new_value = [];
 
     foreach ((array) $value as $old_key => $old_value) {
+      // Checks that $old_value is an array.
+      if (!is_array($old_value)) {
+        throw new MigrateException("The input should be an array of arrays.");
+      }
+
+      // Checks that the key exists.
+      if (!array_key_exists($this->configuration['key'], $old_value)) {
+        throw new MigrateException("The key '" . $this->configuration['key'] . "' does not exist.");
+      }
+
+      // Checks that the value exists
+      if (!array_key_exists($this->configuration['value'], $old_value)) {
+        throw new MigrateException("The key '" . $this->configuration['value'] . "' does not exist.");
+      }
+
       $new_value[$old_value[$this->configuration['key']]] = $old_value[$this->configuration['value']];
     }
 
diff --git a/core/modules/migrate/tests/src/Unit/process/ArrayMapTest.php b/core/modules/migrate/tests/src/Unit/process/ArrayMapTest.php
new file mode 100644
index 0000000..b5953ed
--- /dev/null
+++ b/core/modules/migrate/tests/src/Unit/process/ArrayMapTest.php
@@ -0,0 +1,89 @@
+<?php
+
+namespace Drupal\Tests\migrate\Unit\process;
+
+use Drupal\migrate\Plugin\migrate\process\ArrayMap;
+
+/**
+ * @coversDefaultClass \Drupal\migrate\Plugin\migrate\process\ArrayMap
+ * @group migrate
+ */
+class ArrayMapTest extends MigrateProcessTestCase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    $configuration = [
+      'key' => 'foo',
+      'value' => 'bar',
+    ];
+    $this->plugin = new ArrayMap($configuration, 'map', array());
+    parent::setUp();
+  }
+
+  /**
+   * Tests successful mapping.
+   */
+  public function testExtract() {
+    $source = [
+      ['foo' => 'Foo', 'bar' => 'Bar'],
+      ['foo' => 'foo bar', 'bar' => 'bar foo'],
+    ];
+    $expected = [
+      'Foo' => 'Bar',
+      'foo bar' => 'bar foo',
+    ];
+    $value = $this->plugin->transform($source, $this->migrateExecutable, $this->row, 'destinationproperty');
+    $this->assertSame($value, $expected);
+  }
+
+  /**
+   * Tests non-existent key for the mapping key.
+   *
+   * @expectedException \Drupal\migrate\MigrateException
+   * @expectedExceptionMessage The key 'foo' does not exist.
+   */
+  public function testNonExistentKey() {
+    $source = [
+      ['bar' => 'foo'],
+    ];
+    $this->plugin->transform($source, $this->migrateExecutable, $this->row, 'destinationproperty');
+  }
+
+  /**
+   * Tests non-existent key for the mapping value.
+   *
+   * @expectedException \Drupal\migrate\MigrateException
+   * @expectedExceptionMessage The key 'bar' does not exist.
+   */
+  public function testNonExistentValue() {
+    $source = [
+      ['foo' => 'bar'],
+    ];
+    $this->plugin->transform($source, $this->migrateExecutable, $this->row, 'destinationproperty');
+  }
+
+  /**
+   * Tests one-dimensional array input.
+   *
+   * @expectedException \Drupal\migrate\MigrateException
+   * @expectedExceptionMessage The input should be an array of arrays.
+   */
+  public function testOneDimensionalArrayInput() {
+    $source = ['foo' => 'bar'];
+    $this->plugin->transform($source, $this->migrateExecutable, $this->row, 'destinationproperty');
+  }
+
+  /**
+   * Tests string input.
+   *
+   * @expectedException \Drupal\migrate\MigrateException
+   * @expectedExceptionMessage The input should be an array of arrays.
+   */
+  public function testStringInput() {
+    $source = 'foo';
+    $this->plugin->transform($source, $this->migrateExecutable, $this->row, 'destinationproperty');
+  }
+
+}