diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index 1ebd3f2e6d3..8ec78c83304 100644
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -1075,7 +1075,7 @@ load_dh_buffer(const char *buffer, size_t len)
 	BIO		   *bio;
 	DH		   *dh = NULL;
 
-	bio = BIO_new_mem_buf(unconstify(char *, buffer), len);
+	bio = BIO_new_mem_buf(buffer, len);
 	if (bio == NULL)
 		return NULL;
 	dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL);