diff --git a/nextflow_schema.json b/nextflow_schema.json
index 7ae4b5510047f2e1133758f15787bf6ad76693a4..a0c433072b777fefb3f981f266180cd3c5e8ac3e 100644
--- a/nextflow_schema.json
+++ b/nextflow_schema.json
@@ -93,7 +93,6 @@
             "properties": {
                 "digestion": {
                     "type": "string",
-                    "default": null,
                     "description": "Name of restriction enzyme to automatically set the restriction_site and ligation_site options (hindiii, mboi, dpnii, arima)",
                     "enum": ["hindiii", "mboi", "dpnii", "arima"]
                 },