diff --git a/nixops_aws/backends/ec2.py b/nixops_aws/backends/ec2.py
index 5544334d..172211f6 100644
--- a/nixops_aws/backends/ec2.py
+++ b/nixops_aws/backends/ec2.py
@@ -2041,8 +2041,12 @@ def _check(self, res):
                     device_real
                 )  # boto expects only sd names
 
-                if device_that_boto_expects not in instance.block_device_mapping.keys() and v.get(
-                    "volumeId", None
+                mapped_devices = instance.block_device_mapping.keys()
+
+                if (
+                    device_that_boto_expects not in mapped_devices
+                    and device_real not in mapped_devices
+                    and v.get("volumeId", None)
                 ):
                     res.disks_ok = False
                     res.messages.append(