diff --git a/core/bookloader.py b/core/bookloader.py
index 64208755..d16fe3c0 100755
--- a/core/bookloader.py
+++ b/core/bookloader.py
@@ -521,6 +521,20 @@ def merge_works(w1, w2, user=None):
     #(for example, when w2 has already been deleted)
     if w1 is None or w2 is None or w1.id == w2.id or w1.id is None or w2.id is None:
         return w1
+
+    #don't merge if the works are related.
+    if w2 in w1.works_related_to.all() or w1 in w2.works_related_to.all():
+        return w1
+    
+    # check if one of the works is a series with parts (that have their own isbn)
+    if w1.works_related_from.filter(relation='part'):
+        models.WorkRelation.objects.get_or_create(to_work=w2, from_work=w1, relation='part')
+        return w1
+    if w2.works_related_from.filter(relation='part'):
+        models.WorkRelation.objects.get_or_create(to_work=w1, from_work=w2, relation='part')
+        return w1
+        
+        
     if w2.selected_edition is not None and w1.selected_edition is None:
         #the merge should be reversed
         temp = w1
diff --git a/core/migrations/0014_auto_20180618_1646.py b/core/migrations/0014_auto_20180618_1646.py
new file mode 100644
index 00000000..756c895f
--- /dev/null
+++ b/core/migrations/0014_auto_20180618_1646.py
@@ -0,0 +1,19 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('core', '0013_ebookfile_mobied'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='workrelation',
+            name='relation',
+            field=models.CharField(max_length=15, choices=[(b'translation', b'translation'), (b'revision', b'revision'), (b'sequel', b'sequel'), (b'part', b'part')]),
+        ),
+    ]
diff --git a/core/parameters.py b/core/parameters.py
index 9db6a10c..a7fffae8 100644
--- a/core/parameters.py
+++ b/core/parameters.py
@@ -20,7 +20,7 @@ TEXT_RELATION_CHOICES = (
     ('translation', 'translation'),
     ('revision', 'revision'),
     ('sequel', 'sequel'),
-    ('compilation', 'compilation')
+    ('part', 'part')
 )
 
 ID_CHOICES = (
diff --git a/core/tests.py b/core/tests.py
index 8532df09..d684a9ef 100755
--- a/core/tests.py
+++ b/core/tests.py
@@ -298,7 +298,13 @@ class BookLoaderTests(TestCase):
         # first try to merge work 1 into itself -- should not do anything
         bookloader.merge_works(w1, w1)
         self.assertEqual(models.Work.objects.count(), before + 2)
-
+        
+        # first try to merge related works -- should not do anything
+        rel, created = models.WorkRelation.objects.get_or_create(to_work=w1, from_work=w2, relation='part')
+        bookloader.merge_works(w1, w2)
+        self.assertEqual(models.Work.objects.count(), before + 2)
+        rel.delete()
+        
         # merge the second work into the first
         bookloader.merge_works(e1.work, e2.work)
         self.assertEqual(models.Work.objects.count(), before + 1)