diff --git a/lib/Makefile.include b/lib/Makefile.include
index e109d339..4c44bf6e 100644
--- a/lib/Makefile.include
+++ b/lib/Makefile.include
@@ -24,7 +24,7 @@ Q := @
 endif
 
 # common objects
-OBJS += vector.o systick.o scb.o nvic.o assert.o sync.o
+OBJS += vector.o systick.o scb.o nvic.o assert.o sync.o dwt.o
 
 all: $(SRCLIBDIR)/$(LIBNAME).a