diff --git a/apiserver/common/storage.go b/apiserver/common/storage.go
index <HASH>..<HASH> 100644
--- a/apiserver/common/storage.go
+++ b/apiserver/common/storage.go
@@ -95,7 +95,10 @@ func volumeStorageAttachmentInfo(
 	if err != nil {
 		return nil, errors.Trace(err)
 	}
-	return &storage.StorageAttachmentInfo{devicePath}, nil
+	return &storage.StorageAttachmentInfo{
+		storage.StorageKindBlock,
+		devicePath,
+	}, nil
 }
 
 func filesystemStorageAttachmentInfo(
@@ -117,6 +120,7 @@ func filesystemStorageAttachmentInfo(
 		return nil, errors.Annotate(err, "getting filesystem attachment info")
 	}
 	return &storage.StorageAttachmentInfo{
+		storage.StorageKindFilesystem,
 		filesystemAttachmentInfo.MountPoint,
 	}, nil
 }
diff --git a/storage/storage.go b/storage/storage.go
index <HASH>..<HASH> 100644
--- a/storage/storage.go
+++ b/storage/storage.go
@@ -40,6 +40,9 @@ type StorageInstance struct {
 // instance. StorageAttachmentInfo is based on either a volume attachment
 // or a filesystem attachment, depending on its kind.
 type StorageAttachmentInfo struct {
+	// Kind is the kind of the storage attachment.
+	Kind StorageKind
+
 	// Location is the storage attachment's location: the mount point
 	// for a filesystem-kind storage attachment, and the device path
 	// for a block-kind.
storage: add Kind to StorageAttachmentInfo

(and in apiserver/common)