diff --git a/mellon/models_utils.py b/mellon/models_utils.py
index d2fc4f8..48e38ef 100644
--- a/mellon/models_utils.py
+++ b/mellon/models_utils.py
@@ -19,12 +19,18 @@ from . import models, utils
 def get_issuer(entity_id):
     idp = utils.get_idp(entity_id)
     slug = idp.get('SLUG')
+    issuer = None
     if slug:
         issuer = models.Issuer.objects.filter(slug=slug).first()
         # migrate issuer entity_id based on the slug
         if issuer and issuer.entity_id != entity_id:
             issuer.entity_id = entity_id
             issuer.save()
-    if not slug or not issuer:
-        issuer, _ = models.Issuer.objects.update_or_create(entity_id=entity_id, defaults={'slug': slug})
+
+    if issuer is None:
+        issuer, _ = models.Issuer.objects.get_or_create(entity_id=entity_id)
+        # migrate issuer slug based on the entity_id
+        if issuer.slug != slug:
+            issuer.slug = slug
+            issuer.save()
     return issuer