diff --git a/fast-import.c b/fast-import.c
index 281b8f6a5ef..8342314bb0e 100644
--- a/fast-import.c
+++ b/fast-import.c
@@ -217,7 +217,7 @@ struct hash_list
 
 /* Configured limits on output */
 static unsigned long max_depth = 10;
-static unsigned long max_packsize = -1;
+static unsigned long max_packsize = (1LL << 32) - 1;
 static uintmax_t max_objects = -1;
 
 /* Stats and misc. counters */