diff --git a/lib/Makefile.include b/lib/Makefile.include
index 9fbea244..6c25069d 100644
--- a/lib/Makefile.include
+++ b/lib/Makefile.include
@@ -23,6 +23,9 @@ ifneq ($(V),1)
 Q := @
 endif
 
+# common objects
+OBJS += vector.o systick.o scb.o nvic.o assert.o
+
 all: $(SRCLIBDIR)/$(LIBNAME).a
 
 $(SRCLIBDIR)/$(LIBNAME).a: $(SRCLIBDIR)/$(LIBNAME).ld $(OBJS)
diff --git a/lib/lpc13xx/Makefile b/lib/lpc13xx/Makefile
index bc7e198d..dd460b8f 100644
--- a/lib/lpc13xx/Makefile
+++ b/lib/lpc13xx/Makefile
@@ -28,7 +28,7 @@ CFLAGS		= -Os -g -Wall -Wextra -I../../include -fno-common \
 		  -ffunction-sections -fdata-sections -MD
 # ARFLAGS	= rcsv
 ARFLAGS		= rcs
-OBJS		= gpio.o assert.o vector.o
+OBJS		= gpio.o
 
 VPATH += ../cm3
 
diff --git a/lib/lpc17xx/Makefile b/lib/lpc17xx/Makefile
index d1da64af..f5fa7927 100644
--- a/lib/lpc17xx/Makefile
+++ b/lib/lpc17xx/Makefile
@@ -28,7 +28,7 @@ CFLAGS		= -O0 -g -Wall -Wextra -I../../include -fno-common \
 		  -ffunction-sections -fdata-sections -MD
 # ARFLAGS	= rcsv
 ARFLAGS		= rcs
-OBJS		= gpio.o vector.o assert.o
+OBJS		= gpio.o
 
 VPATH += ../cm3
 
diff --git a/lib/lpc43xx/Makefile b/lib/lpc43xx/Makefile
index 6e08ea0e..a3a5361f 100644
--- a/lib/lpc43xx/Makefile
+++ b/lib/lpc43xx/Makefile
@@ -31,8 +31,7 @@ CFLAGS		= -O2 -g3 -Wall -Wextra -I../../include -fno-common \
 		  -mfloat-abi=hard -mfpu=fpv4-sp-d16
 # ARFLAGS	= rcsv
 ARFLAGS		= rcs
-OBJS		= gpio.o vector.o scu.o i2c.o ssp.o nvic.o systick.o \
-		  assert.o
+OBJS		= gpio.o scu.o i2c.o ssp.o
 
 VPATH += ../cm3
 
diff --git a/lib/stm32/f1/Makefile b/lib/stm32/f1/Makefile
index a2f7bf28..2bd5ff09 100644
--- a/lib/stm32/f1/Makefile
+++ b/lib/stm32/f1/Makefile
@@ -28,10 +28,10 @@ CFLAGS		= -Os -g -Wall -Wextra -I../../../include -fno-common \
 		  -ffunction-sections -fdata-sections -MD -DSTM32F1
 # ARFLAGS	= rcsv
 ARFLAGS		= rcs
-OBJS		= vector.o rcc.o gpio.o usart.o adc.o spi.o flash.o nvic.o \
-		  rtc.o i2c.o dma.o systick.o exti.o scb.o ethernet.o \
+OBJS		= rcc.o gpio.o usart.o adc.o spi.o flash.o \
+		  rtc.o i2c.o dma.o exti.o ethernet.o \
 		  usb_f103.o usb.o usb_control.o usb_standard.o can.o \
-		  timer.o usb_f107.o desig.o crc.o assert.o dac.o iwdg.o pwr.o
+		  timer.o usb_f107.o desig.o crc.o dac.o iwdg.o pwr.o
 
 VPATH += ../../usb:../:../../cm3
 
diff --git a/lib/stm32/f2/Makefile b/lib/stm32/f2/Makefile
index c127d61f..69521da4 100644
--- a/lib/stm32/f2/Makefile
+++ b/lib/stm32/f2/Makefile
@@ -28,8 +28,8 @@ CFLAGS		= -Os -g -Wall -Wextra -I../../../include -fno-common \
 		  -ffunction-sections -fdata-sections -MD -DSTM32F2
 # ARFLAGS	= rcsv
 ARFLAGS		= rcs
-OBJS		= vector.o rcc.o gpio.o usart.o spi.o flash.o nvic.o \
-		  i2c.o systick.o exti.o scb.o timer.o assert.o
+OBJS		= rcc.o gpio.o usart.o spi.o flash.o nvic.o \
+		  i2c.o exti.o timer.o
 
 VPATH += ../../usb:../:../../cm3
 
diff --git a/lib/stm32/f4/Makefile b/lib/stm32/f4/Makefile
index fd0b2793..180e537c 100644
--- a/lib/stm32/f4/Makefile
+++ b/lib/stm32/f4/Makefile
@@ -29,10 +29,9 @@ CFLAGS		= -Os -g -Wall -Wextra -I../../../include -fno-common \
 		  -ffunction-sections -fdata-sections -MD -DSTM32F4
 # ARFLAGS	= rcsv
 ARFLAGS		= rcs
-OBJS		= vector.o rcc.o gpio.o usart.o spi.o flash.o nvic.o \
-		  i2c.o systick.o exti.o scb.o pwr.o timer.o \
-		  usb.o usb_standard.o usb_control.o usb_f107.o \
-		  assert.o
+OBJS		= rcc.o gpio.o usart.o spi.o flash.o nvic.o \
+		  i2c.o exti.o pwr.o timer.o \
+		  usb.o usb_standard.o usb_control.o usb_f107.o
 
 VPATH += ../../usb:../:../../cm3