diff --git a/helpers/Dojo/SharedAssignmentHelper.ts b/helpers/Dojo/SharedAssignmentHelper.ts
index 007f7bf29b2ae2525a3f4e2f785da5aff3579491..8b52f8aa55fe3c4ce9c34f40f10545f59c377d29 100644
--- a/helpers/Dojo/SharedAssignmentHelper.ts
+++ b/helpers/Dojo/SharedAssignmentHelper.ts
@@ -15,9 +15,11 @@ class SharedAssignmentHelper {
 
                 immutable: {
                     elements: {
-                        properties: {
+                        properties        : {
+                            path: { type: 'string' }
+                        },
+                        optionalProperties: {
                             description: { type: 'string' },
-                            path       : { type: 'string' },
                             isDirectory: { type: 'boolean' }
                         }
                     }
diff --git a/types/Dojo/ImmutableFileDescriptor.ts b/types/Dojo/ImmutableFileDescriptor.ts
index 4a05c256e47258aab0f270db59d1cfa983db9fb4..4597de7bef821c5cba5775fcb3a6ba069272775d 100644
--- a/types/Dojo/ImmutableFileDescriptor.ts
+++ b/types/Dojo/ImmutableFileDescriptor.ts
@@ -1,7 +1,7 @@
 interface ImmutableFileDescriptor {
-    description: string,
+    description?: string,
     path: string,
-    isDirectory: boolean,
+    isDirectory?: boolean,
 }