diff --git a/types/Dojo/AssignmentFile.ts b/types/Dojo/AssignmentFile.ts
index 04de8bab72145137a1032a34214c2253ba6dbfea..61c826cfe7576927fb2a19f9eaeada9f696fb16c 100644
--- a/types/Dojo/AssignmentFile.ts
+++ b/types/Dojo/AssignmentFile.ts
@@ -8,7 +8,7 @@ interface AssignmentFile {
     immutable: Array<ImmutableFileDescriptor>
 
     result: {
-        container: string, volume: string
+        container: string, volume?: string
     }
 }