diff --git a/source/dub/internal/vibecompat/data/json.d b/source/dub/internal/vibecompat/data/json.d
index 9162969..dfe079f 100644
--- a/source/dub/internal/vibecompat/data/json.d
+++ b/source/dub/internal/vibecompat/data/json.d
@@ -163,7 +163,7 @@
 	const(Json) opIndex(string key) const {
 		checkType!(Json[string])();
 		if( auto pv = key in m_object ) return *pv;
-		Json ret = Json.Undefined;
+		Json ret = Json.undefined;
 		ret.m_string = key;
 		return ret;
 	}