diff --git a/Makefile b/Makefile
index 475516b..a48f5f1 100644
--- a/Makefile
+++ b/Makefile
@@ -5,6 +5,7 @@
 #CFLAGS+=-DHAS_LCHFLAGS
 #CFLAGS+=-DHAS_TRUNCATE64
 #CFLAGS+=-DHAS_STAT64
+CFLAGS+=-m64
 
 all:	fstest