diff --git a/app/src/main/kotlin/de/ids_mannheim/korapxmltools/formatters/KrillJsonGenerator.kt b/app/src/main/kotlin/de/ids_mannheim/korapxmltools/formatters/KrillJsonGenerator.kt
index 905a829..e111fa7 100644
--- a/app/src/main/kotlin/de/ids_mannheim/korapxmltools/formatters/KrillJsonGenerator.kt
+++ b/app/src/main/kotlin/de/ids_mannheim/korapxmltools/formatters/KrillJsonGenerator.kt
@@ -17,8 +17,8 @@
     fun resolveHeaderMetadata(
         textId: String,
         textHeaderMetadata: Map<String, Any>,
-        corpusMetadata: Map<String, out Map<String, Any>>,
-        docMetadata: Map<String, out Map<String, Any>>
+        corpusMetadata: Map<String, Map<String, Any>>,
+        docMetadata: Map<String, Map<String, Any>>
     ): MutableMap<String, Any> {
         val resolved = mutableMapOf<String, Any>()
         val textIdWithSlashes = textId.replace("_", "/").replace(".", "/")