diff --git a/common/Makefile b/common/Makefile
index d3888d61e8e3f6346e7cf943845dd751f1b9c7bc..8d4a4269520fecce1e576b919cdee83cf2af31a5 100644
--- a/common/Makefile
+++ b/common/Makefile
@@ -153,7 +153,7 @@ COBJS-$(CONFIG_LYNXKDI) += lynxkdi.o
 COBJS-$(CONFIG_USB_KEYBOARD) += usb_kbd.o
 COBJS-$(CONFIG_DDR_SPD) += ddr_spd.o
 
-COBJS	:= $(sort COBJS-y)
+COBJS	:= $(sort $(COBJS-y))
 SRCS	:= $(AOBJS:.o=.S) $(COBJS:.o=.c)
 OBJS	:= $(addprefix $(obj),$(AOBJS) $(COBJS))
 
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 7f817dcf220468479d3492e2116e8346ed9e543a..94bc518a5c15db3c5dfb115cca9d9ac9c6ca3c0b 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -59,7 +59,7 @@ COBJS-$(CONFIG_RTC_RX8025) += rx8025.o
 COBJS-$(CONFIG_RTC_S3C24X0) += s3c24x0_rtc.o
 COBJS-$(CONFIG_RTC_X1205) += x1205.o
 
-COBJS	:= $(sort COBJS-y)
+COBJS	:= $(sort $(COBJS-y))
 SRCS	:= $(COBJS:.o=.c)
 OBJS	:= $(addprefix $(obj),$(COBJS))
 
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index adb0a589bafe0172e90a17c7e607d5f8a15c3e89..eafe543e36ea83cc82560a8a987da78555f26695 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -39,7 +39,7 @@ COBJS-$(CONFIG_XILINX_UARTLITE) += serial_xuartlite.o
 COBJS-$(CONFIG_SCIF_CONSOLE) += serial_sh.o
 COBJS-$(CONFIG_USB_TTY) += usbtty.o
 
-COBJS	:= $(sort COBJS-y)
+COBJS	:= $(sort $(COBJS-y))
 SRCS	:= $(COBJS:.o=.c)
 OBJS	:= $(addprefix $(obj),$(COBJS))