diff --git a/crypto/pkcs7/example.c b/crypto/pkcs7/example.c
index f6656be28..c993947cc 100644
--- a/crypto/pkcs7/example.c
+++ b/crypto/pkcs7/example.c
@@ -3,6 +3,7 @@
 #include <string.h>
 #include <openssl/pkcs7.h>
 #include <openssl/asn1_mac.h>
+#include <openssl/x509.h>
 
 int add_signed_time(PKCS7_SIGNER_INFO *si)
 	{