diff --git a/Makefile.x86_64 b/Makefile.x86_64
index f14a8a8ff..795813d92 100644
--- a/Makefile.x86_64
+++ b/Makefile.x86_64
@@ -163,6 +163,8 @@ endif
 endif
 
 
+FCOMMON_OPT += -fno-tree-vectorize
+
 ifeq ($(OSNAME), Interix)
 ARFLAGS		= -m x64
 endif