diff --git a/json-schema/schema.json b/json-schema/schema.json
index dfe3f21..cf5500e 100644
--- a/json-schema/schema.json
+++ b/json-schema/schema.json
@@ -185,7 +185,7 @@
         },
         "cmip6:data_specs_version": {
           "type": "string",
-          "pattern": "^[[:digit:]]\\{2,2\\}\\.[[:digit:]]\\{2,2\\}\\.[[:digit:]]\\{2,2\\}$"
+          "pattern": "^[0-9]{2,2}\\.[0-9]{2,2}\\.[0-9]{2,2}$"
         },
         "cmip6:experiment": {
           "type": "string",
@@ -1349,7 +1349,7 @@
         },
         "cmip6:variant_label": {
           "type": "string",
-          "pattern": "r[[:digit:]]\\{1,\\}i[[:digit:]]\\{1,\\}p[[:digit:]]\\{1,\\}f[[:digit:]]\\{1,\\}$"
+          "pattern": "r[0-9]{1,}i[0-9]{1,}p[0-9]{1,}f[0-9]{1,}$"
         }
       },
       "patternProperties": {