diff --git a/base/manifest-schema.json b/base/manifest-schema.json
index bb0f006..a98907b 100644
--- a/base/manifest-schema.json
+++ b/base/manifest-schema.json
@@ -36,7 +36,8 @@
 			"type": "object",
 			"properties": {
 				"size": {
-					"type": "integer"
+					"type": "integer",
+					"minimum": 1
 				}
 			},
 			"required": ["size"]