diff --git a/lib/crypto/Makefile b/lib/crypto/Makefile
index 946cc3a..1605908 100644
--- a/lib/crypto/Makefile
+++ b/lib/crypto/Makefile
@@ -53,6 +53,7 @@
 obj-$(CONFIG_$(SPL_)PKCS7_MESSAGE_PARSER) += pkcs7_message.o
 pkcs7_message-y := \
 	pkcs7.asn1.o \
+	pkcs7_helper.o \
 	pkcs7_parser.o
 obj-$(CONFIG_$(SPL_)PKCS7_VERIFY) += pkcs7_verify.o