diff --git a/src/_cffi_src/openssl/dh.py b/src/_cffi_src/openssl/dh.py
index 9b776b9..a405da0 100644
--- a/src/_cffi_src/openssl/dh.py
+++ b/src/_cffi_src/openssl/dh.py
@@ -38,6 +38,8 @@
 
 MACROS = """
 int DH_generate_parameters_ex(DH *, int, int, BN_GENCB *);
+DH *d2i_DHparams_bio(BIO *, DH **);
+int i2d_DHparams_bio(BIO *, DH *);
 """
 
 CUSTOMIZATIONS = """