diff --git a/server/migrate-v1 b/server/migrate-v1
index 6fc4f82..6c93b76 100755
--- a/server/migrate-v1
+++ b/server/migrate-v1
@@ -123,15 +123,17 @@ def import_users(v1_data_dir, v1_session, v2_session, no_data=False):
         }[row['avatarStyle']]
         v2_session.add(user)
 
-        if user.avatar_style == db.User.AVATAR_MANUAL and not no_data:
+        if user.avatar_style == db.User.AVATAR_MANUAL:
             source_avatar_path = os.path.join(
                 v1_data_dir, 'public_html', 'data', 'avatars', str(user.user_id))
-            avatar_content = read_file(source_avatar_path)
-            image = images.Image(avatar_content)
-            image.resize_fill(
-                int(config.config['thumbnails']['avatar_width']),
-                int(config.config['thumbnails']['avatar_height']))
-            files.save('avatars/' + user.name.lower() + '.png', image.to_png())
+            target_avatar_path = 'avatars/' + user.name.lower() + '.png'
+            if not no_data and not files.has(target_avatar_path):
+                avatar_content = read_file(source_avatar_path)
+                image = images.Image(avatar_content)
+                image.resize_fill(
+                    int(config.config['thumbnails']['avatar_width']),
+                    int(config.config['thumbnails']['avatar_height']))
+                files.save(target_avatar_path, image.to_png())
     counter = exec_scalar(v1_session, 'SELECT MAX(id) FROM users') + 1
     v2_session.execute('ALTER SEQUENCE user_id_seq RESTART WITH %d' % counter)
     v2_session.commit()
@@ -243,12 +245,16 @@ def _import_post_content_for_post(
         'data',
         'posts',
         row['name'] + '-custom-thumb')
-    post_content = read_file(source_content_path)
-    files.save(posts.get_post_content_path(post), post_content)
-    if os.path.exists(source_thumb_path):
+    target_content_path = posts.get_post_content_path(post)
+    target_thumb_path = posts.get_post_thumbnail_backup_path(post)
+    if not files.has(target_content_path):
+        post_content = read_file(source_content_path)
+        files.save(target_content_path, post_content)
+    if os.path.exists(source_thumb_path) and not files.has(target_thumb_path):
         thumb_content = read_file(source_thumb_path)
-        files.save(posts.get_post_thumbnail_backup_path(post), thumb_content)
-    posts.generate_post_thumbnail(post)
+        files.save(target_thumb_path, thumb_content)
+    if not files.has(posts.get_post_thumbnail_path(post)):
+        posts.generate_post_thumbnail(post)
 
 def import_post_content(unused_post_ids, v1_data_dir, v1_session, v2_session):
     rows = list(exec_query(v1_session, 'SELECT * FROM posts'))