diff --git a/base/manifest-schema.json b/base/manifest-schema.json
index b9adbbe..17dc233 100644
--- a/base/manifest-schema.json
+++ b/base/manifest-schema.json
@@ -45,7 +45,7 @@
 				"sources": {
 					"type": "object",
 					"patternProperties": {
-						"^\\w+$": {
+						"^[^\/\\0]+$": {
 							"type": "array",
 							"items": {
 								"type": "string",