diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/notes/FanoutBucket.java b/org.eclipse.jgit/src/org/eclipse/jgit/notes/FanoutBucket.java
index ea904cd1d..79fbb09ec 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/notes/FanoutBucket.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/notes/FanoutBucket.java
@@ -260,8 +260,8 @@ class FanoutBucket extends InMemoryNoteBucket {
 	}
 
 	ObjectId getTreeId() {
-		try {
-			return new ObjectInserter.Formatter().idFor(build(false, null));
+		try (ObjectInserter.Formatter f = new ObjectInserter.Formatter()) {
+			return f.idFor(build(false, null));
 		} catch (IOException e) {
 			// should never happen as we are not inserting
 			throw new RuntimeException(e);