diff --git a/library/Makefile b/library/Makefile
index b155c72..5721d7e 100644
--- a/library/Makefile
+++ b/library/Makefile
@@ -56,6 +56,7 @@
 		ecjpake.o	ecp.o				\
 		ecp_curves.o	entropy.o	entropy_poll.o	\
 		error.o		gcm.o		havege.o	\
+		hkdf.o						\
 		hmac_drbg.o	md.o		md2.o		\
 		md4.o		md5.o		md_wrap.o	\
 		memory_buffer_alloc.o		oid.o		\