1 files changed, 1 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index a832a4f..730b8a4 100644
--- a/Makefile
+++ b/Makefile
@@ -3,6 +3,6 @@ ffi := -default-ann "allowFFI true" -export-header export.h
 caux := caux.c
 
 def:
-	mlton $(history) $(ffi) ccross.mlb $(caux)
+	mlton $(history) $(ffi) -default-type word64 ccross.mlb $(caux)
 clean:
 	rm -f ccross export.h