diff --git a/gns3server/schemas/common.py b/gns3server/schemas/common.py
index ad6d6866..fbbb9b9b 100644
--- a/gns3server/schemas/common.py
+++ b/gns3server/schemas/common.py
@@ -43,7 +43,7 @@ class CustomAdapter(BaseModel):
     """
 
     adapter_number: int
-    port_name: str
+    port_name: Optional[str] = None
     adapter_type: Optional[str] = None
     mac_address: Optional[str] = Field(None, regex="^([0-9a-fA-F]{2}[:]){5}([0-9a-fA-F]{2})$")