diff --git a/src/main/kotlin/biokotlin/util/MergeGVCFUtils.kt b/src/main/kotlin/biokotlin/util/MergeGVCFUtils.kt
index 7dff7506..ea4cb951 100644
--- a/src/main/kotlin/biokotlin/util/MergeGVCFUtils.kt
+++ b/src/main/kotlin/biokotlin/util/MergeGVCFUtils.kt
@@ -197,6 +197,8 @@ private suspend fun writeOutputVCF(
 
     }
 
+    writer?.close()
+
 }
 
 /**