diff --git a/core/modules/comment/src/Plugin/migrate/source/d7/Comment.php b/core/modules/comment/src/Plugin/migrate/source/d7/Comment.php
index e643eb1..1ef4aff 100644
--- a/core/modules/comment/src/Plugin/migrate/source/d7/Comment.php
+++ b/core/modules/comment/src/Plugin/migrate/source/d7/Comment.php
@@ -31,12 +31,23 @@ public function query() {
    */
   public function prepareRow(Row $row) {
     $cid = $row->getSourceProperty('cid');
-
     $node_type = $row->getSourceProperty('node_type');
-    $comment_type = 'comment_node_' . $node_type;
-    $row->setSourceProperty('comment_type', 'comment_node_' . $node_type);
 
-    foreach (array_keys($this->getFields('comment', $comment_type)) as $field) {
+    // Migrate forum and article comments using standard D8 comment types.
+    switch ($node_type) {
+      case 'forum':
+        $comment_type = 'comment_forum';
+        break;
+      case 'article':
+        $comment_type = 'comment';
+        break;
+      default:
+        $comment_type = 'comment_node_' . $node_type;
+    }
+    $row->setSourceProperty('comment_type', $comment_type);
+
+    $d7_bundle = 'comment_node_' . $node_type;
+    foreach (array_keys($this->getFields('comment', $d7_bundle)) as $field) {
       $row->setSourceProperty($field, $this->getFieldValues('comment', $field, $cid));
     }
 
diff --git a/core/modules/comment/src/Plugin/migrate/source/d7/CommentType.php b/core/modules/comment/src/Plugin/migrate/source/d7/CommentType.php
index 2ac7c97..8b85786 100644
--- a/core/modules/comment/src/Plugin/migrate/source/d7/CommentType.php
+++ b/core/modules/comment/src/Plugin/migrate/source/d7/CommentType.php
@@ -27,10 +27,15 @@ class CommentType extends DrupalSqlBase {
    * {@inheritdoc}
    */
   public function query() {
-    return $this->select('field_config_instance', 'fci')
+    $query = $this->select('field_config_instance', 'fci')
       ->distinct()
       ->fields('fci', ['bundle'])
       ->condition('fci.entity_type', 'comment');
+
+    // Forum and article use standard D8 comment types. Exclude these bundles.
+    $query->condition('fci.bundle', array('comment_node_article', 'comment_node_forum'), 'NOT IN');
+
+    return $query;
   }
 
   /**
diff --git a/core/modules/field/src/Plugin/migrate/source/d7/FieldInstance.php b/core/modules/field/src/Plugin/migrate/source/d7/FieldInstance.php
index d06336e..6362b74 100644
--- a/core/modules/field/src/Plugin/migrate/source/d7/FieldInstance.php
+++ b/core/modules/field/src/Plugin/migrate/source/d7/FieldInstance.php
@@ -30,6 +30,9 @@ public function query() {
     $query->innerJoin('field_config', 'fc', 'fci.field_id = fc.id');
     $query->addField('fc', 'data', 'field_data');
 
+    // Forum and article use standard D8 comment types. Exclude these bundles.
+    $query->condition('fci.bundle', array('comment_node_article', 'comment_node_forum'), 'NOT IN');
+
     // Optionally filter by entity type and bundle.
     if (isset($this->configuration['entity_type'])) {
       $query->condition('fci.entity_type', $this->configuration['entity_type']);
diff --git a/core/modules/field/src/Plugin/migrate/source/d7/FieldInstancePerFormDisplay.php b/core/modules/field/src/Plugin/migrate/source/d7/FieldInstancePerFormDisplay.php
index ac599ec..15a7646 100644
--- a/core/modules/field/src/Plugin/migrate/source/d7/FieldInstancePerFormDisplay.php
+++ b/core/modules/field/src/Plugin/migrate/source/d7/FieldInstancePerFormDisplay.php
@@ -30,6 +30,10 @@ public function query() {
         'module',
       ]);
     $query->join('field_config', 'fc', 'fci.field_id = fc.id');
+
+    // Forum and article use standard D8 comment types. Exclude these bundles.
+    $query->condition('fci.bundle', array('comment_node_article', 'comment_node_forum'), 'NOT IN');
+
     return $query;
   }
 
diff --git a/core/modules/field/src/Plugin/migrate/source/d7/FieldInstancePerViewMode.php b/core/modules/field/src/Plugin/migrate/source/d7/FieldInstancePerViewMode.php
index 7339e76..3cb7067 100644
--- a/core/modules/field/src/Plugin/migrate/source/d7/FieldInstancePerViewMode.php
+++ b/core/modules/field/src/Plugin/migrate/source/d7/FieldInstancePerViewMode.php
@@ -46,6 +46,10 @@ public function query() {
       ->fields('fci', ['entity_type', 'bundle', 'field_name', 'data'])
       ->fields('fc', ['type']);
     $query->join('field_config', 'fc', 'fc.field_name = fci.field_name');
+
+    // Forum and article use standard D8 comment types. Exclude these bundles.
+    $query->condition('fci.bundle', array('comment_node_article', 'comment_node_forum'), 'NOT IN');
+
     return $query;
   }