diff --git a/astrocyte_pkg.yml b/astrocyte_pkg.yml
index 7c34bde1e06c081a27fc30ffa010ad627b8efebf..49e81c72b209bc56e665924dcb4d05dd18643053 100755
--- a/astrocyte_pkg.yml
+++ b/astrocyte_pkg.yml
@@ -151,10 +151,11 @@ workflow_parameters:
       10x cellranger version.
 
   - id: astrocyte
-    type: string
+    type: select
+    choices:
+      - [ 'true', 'true' ]
     required: true
     default: 'true'
-    regex: "true"
     description: |
       Ensure configuraton for astrocyte.