diff --git a/nova/db/api.py b/nova/db/api.py
index 67d8e7618..4acff8a99 100644
--- a/nova/db/api.py
+++ b/nova/db/api.py
@@ -785,9 +785,12 @@ def network_delete_safe(context, network_id):
     return IMPL.network_delete_safe(context, network_id)
 
 
-def network_disassociate(context, network_id):
-    """Disassociate the network from project or raise if it does not exist."""
-    return IMPL.network_disassociate(context, network_id)
+def network_disassociate(context, network_id, disassociate_host=True,
+                         disassociate_project=True):
+    """Disassociate the network from project or host and raise if it does
+    not exist."""
+    return IMPL.network_disassociate(context, network_id, disassociate_host,
+                                     disassociate_project)
 
 
 def network_get(context, network_id, project_only="allow_none"):
diff --git a/nova/db/sqlalchemy/api.py b/nova/db/sqlalchemy/api.py
index 29c40bb69..ec85ddcef 100644
--- a/nova/db/sqlalchemy/api.py
+++ b/nova/db/sqlalchemy/api.py
@@ -2135,9 +2135,14 @@ def network_delete_safe(context, network_id):
 
 
 @require_admin_context
-def network_disassociate(context, network_id):
-    network_update(context, network_id, {'project_id': None,
-                                         'host': None})
+def network_disassociate(context, network_id, disassociate_host,
+                         disassociate_project):
+    net_update = {}
+    if disassociate_project:
+        net_update['project_id'] = None
+    if disassociate_host:
+        net_update['host'] = None
+    network_update(context, network_id, net_update)
 
 
 @require_context