diff --git a/minios.mk b/minios.mk
index b0d9f71..9958554 100644
--- a/minios.mk
+++ b/minios.mk
@@ -12,6 +12,8 @@ DEF_CFLAGS += $(call cc-option,$(CC),-fgnu89-inline)
 DEF_CFLAGS += -Wstrict-prototypes -Wnested-externs -Wpointer-arith -Winline
 DEF_CPPFLAGS += -D__XEN_INTERFACE_VERSION__=$(XEN_INTERFACE_VERSION)
 
+$(OBJ_DIR)/lib/string.o: CFLAGS += -ffreestanding
+
 DEF_ASFLAGS += -D__ASSEMBLY__
 DEF_LDFLAGS +=