diff --git a/src/SOL005/definitions/SOL005_def.yaml b/src/SOL005/definitions/SOL005_def.yaml
index c7e2a78180eb0ad3a2e80d01c35e681994b00c43..29fb9e1a492efc7e67a1d669e3e2fc252a14a039 100644
--- a/src/SOL005/definitions/SOL005_def.yaml
+++ b/src/SOL005/definitions/SOL005_def.yaml
@@ -278,8 +278,6 @@ definitions:
         type: array
         items:
           type: object
-          required:
-            - version
           properties:
             version:
               description: >