diff --git a/crypto/des/des.h b/crypto/des/des.h
index cc95af823..8ec7b90f8 100644
--- a/crypto/des/des.h
+++ b/crypto/des/des.h
@@ -66,6 +66,10 @@
 #include <openssl/opensslconf.h> /* DES_LONG */
 #include <openssl/e_os2.h>	/* OPENSSL_EXTERN */
 
+#ifndef OPENSSL_NO_OLD_DES_SUPPORT
+# include <openssl/des_old.h>
+#endif
+
 #ifdef OPENSSL_BUILD_SHLIBCRYPTO
 # undef OPENSSL_EXTERN
 # define OPENSSL_EXTERN OPENSSL_EXPORT