diff --git a/Makefile.am b/Makefile.am
index 54ee508..e781f48 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -116,7 +116,8 @@
   ndn-cpp/encoding/element-listener.cpp \
   ndn-cpp/encoding/oid.cpp \
   ndn-cpp/encoding/wire-format.cpp \
-  ndn-cpp/encoding/der/der.hpp \
+  ndn-cpp/encoding/der/der-exception.cpp ndn-cpp/encoding/der/der-exception.hpp \
+  ndn-cpp/encoding/der/der.cpp ndn-cpp/encoding/der/der.hpp \
   ndn-cpp/encoding/der/visitor/no-arguments-visitor.cpp ndn-cpp/encoding/der/visitor/no-arguments-visitor.hpp \
   ndn-cpp/encoding/der/visitor/simple-visitor.cpp ndn-cpp/encoding/der/visitor/simple-visitor.hpp \
   ndn-cpp/encoding/der/visitor/visitor.hpp \