diff --git a/cmd/gen-jsonschema/main.go b/cmd/gen-jsonschema/main.go
index f4d35364f..856c3a4d0 100644
--- a/cmd/gen-jsonschema/main.go
+++ b/cmd/gen-jsonschema/main.go
@@ -17,6 +17,10 @@ func main() {
 	}
 
 	schema := r.Reflect(&dalec.Spec{})
+	if schema.PatternProperties == nil {
+		schema.PatternProperties = make(map[string]*jsonschema.Schema)
+	}
+	schema.PatternProperties["^x-"] = &jsonschema.Schema{}
 
 	dt, err := json.MarshalIndent(schema, "", "\t")
 	if err != nil {
diff --git a/docs/spec.schema.json b/docs/spec.schema.json
index 5ee7e32f4..95f3ecc07 100644
--- a/docs/spec.schema.json
+++ b/docs/spec.schema.json
@@ -1250,5 +1250,8 @@
 			],
 			"description": "TestStep is a wrapper for [BuildStep] to include checks on stdio streams"
 		}
+	},
+	"patternProperties": {
+		"^x-": true
 	}
 }
\ No newline at end of file