diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/storage/file/ObjectDirectory.java b/org.eclipse.jgit/src/org/eclipse/jgit/storage/file/ObjectDirectory.java
index ac48d2a4b..021a91b6d 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/storage/file/ObjectDirectory.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/storage/file/ObjectDirectory.java
@@ -482,7 +482,7 @@ InsertLooseObjectResult insertUnpackedObject(File tmp, ObjectId id,
 			return InsertLooseObjectResult.EXISTS_LOOSE;
 		}
 		if (tmp.renameTo(dst)) {
-			tmp.setReadOnly();
+			dst.setReadOnly();
 			unpackedObjectCache.add(id);
 			return InsertLooseObjectResult.INSERTED;
 		}
@@ -493,6 +493,7 @@ InsertLooseObjectResult insertUnpackedObject(File tmp, ObjectId id,
 		//
 		dst.getParentFile().mkdir();
 		if (tmp.renameTo(dst)) {
+			dst.setReadOnly();
 			unpackedObjectCache.add(id);
 			return InsertLooseObjectResult.INSERTED;
 		}