diff --git a/src/libutil/archive.cc b/src/libutil/archive.cc
index f1479329f..03534abc4 100644
--- a/src/libutil/archive.cc
+++ b/src/libutil/archive.cc
@@ -27,7 +27,7 @@ struct ArchiveSettings : Config
         #endif
         "use-case-hack",
         "Whether to enable a Darwin-specific hack for dealing with file name collisions."};
-    Setting<bool> preallocateContents{this, true, "preallocate-contents",
+    Setting<bool> preallocateContents{this, false, "preallocate-contents",
         "Whether to preallocate files when writing objects with known size."};
 };