diff --git a/core/modules/migrate_drupal/src/Plugin/migrate/source/d7/FieldableEntity.php b/core/modules/migrate_drupal/src/Plugin/migrate/source/d7/FieldableEntity.php
index 9527513..a6b804d 100644
--- a/core/modules/migrate_drupal/src/Plugin/migrate/source/d7/FieldableEntity.php
+++ b/core/modules/migrate_drupal/src/Plugin/migrate/source/d7/FieldableEntity.php
@@ -32,6 +32,22 @@ protected function getFields($entity_type, $bundle = NULL) {
   }
 
   /**
+   * Returns the field labels for attached fields.
+   *
+   * @param string $entity_type
+   *   The entity type ID.
+   * @param string|null $bundle
+   *   (optional) The bundle.
+   */
+  protected function getFieldLabels($entity_type, $bundle = NULL) {
+    foreach ($this->getFields($entity_type, $bundle) as $field_name => $instance) {
+      $data = !empty($instance['data']) ? $instance['data'] : '';
+      $data = unserialize($data);
+      $fields[$field_name] = $data['label'];
+    }
+  }
+
+  /**
    * Retrieves field values for a single field of a single entity.
    *
    * @param string $entity_type
diff --git a/core/modules/node/src/Plugin/migrate/source/d6/Node.php b/core/modules/node/src/Plugin/migrate/source/d6/Node.php
index ffa2659..9eb64b6 100644
--- a/core/modules/node/src/Plugin/migrate/source/d6/Node.php
+++ b/core/modules/node/src/Plugin/migrate/source/d6/Node.php
@@ -148,6 +148,11 @@ public function fields() {
       'tnid' => $this->t('The translation set id for this node'),
       'timestamp' => $this->t('The timestamp the latest revision of this node was created.'),
     ];
+
+    // Attached fields.
+    $bundle = isset($this->configuration['node_type']) ? $this->configuration['node_type'] : NULL;
+    $fields += $this->getFieldLabels('node', $bundle);
+
     return $fields;
   }
 
diff --git a/core/modules/node/src/Plugin/migrate/source/d7/Node.php b/core/modules/node/src/Plugin/migrate/source/d7/Node.php
index 451905c..23252b0 100644
--- a/core/modules/node/src/Plugin/migrate/source/d7/Node.php
+++ b/core/modules/node/src/Plugin/migrate/source/d7/Node.php
@@ -138,6 +138,11 @@ public function fields() {
       'tnid' => $this->t('The translation set id for this node'),
       'timestamp' => $this->t('The timestamp the latest revision of this node was created.'),
     ];
+
+    // Attached fields.
+    $bundle = isset($this->configuration['node_type']) ? $this->configuration['node_type'] : NULL;
+    $fields += $this->getFieldLabels('node', $bundle);
+
     return $fields;
   }
 
diff --git a/core/modules/taxonomy/src/Plugin/migrate/source/d7/Term.php b/core/modules/taxonomy/src/Plugin/migrate/source/d7/Term.php
index 518b9f7..abe59c8 100644
--- a/core/modules/taxonomy/src/Plugin/migrate/source/d7/Term.php
+++ b/core/modules/taxonomy/src/Plugin/migrate/source/d7/Term.php
@@ -49,6 +49,11 @@ public function fields() {
       'parent' => $this->t("The Drupal term IDs of the term's parents."),
       'format' => $this->t("Format of the term description."),
     ];
+
+    // Attached fields.
+    $bundle = isset($this->configuration['bundle']) ? $this->configuration['bundle'] : NULL;
+    $fields += $this->getFieldLabels('taxonomy_term', $bundle);
+
     return $fields;
   }
 
diff --git a/core/modules/user/src/Plugin/migrate/source/d7/User.php b/core/modules/user/src/Plugin/migrate/source/d7/User.php
index 408d998..db1518a 100644
--- a/core/modules/user/src/Plugin/migrate/source/d7/User.php
+++ b/core/modules/user/src/Plugin/migrate/source/d7/User.php
@@ -54,6 +54,9 @@ public function fields() {
         ->fetchAllKeyed();
     }
 
+    // Attached fields.
+    $fields += $this->getFieldLabels('user');
+
     return $fields;
   }