diff --git a/libtransmission/crypto.h b/libtransmission/crypto.h
--- a/libtransmission/crypto.h
+++ b/libtransmission/crypto.h
@@ -34,6 +34,35 @@ enum
     KEY_LEN = 96
 };
 
+#if (defined(LIBRESSL_VERSION_NUMBER) && (LIBRESSL_VERSION_NUMBER >= 0x3050000fL))
+struct dh_st
+	{
+	/* This first argument is used to pick up errors when
+	 * a DH is passed instead of a EVP_PKEY */
+	int pad;
+	int version;
+	BIGNUM *p;
+	BIGNUM *g;
+	long length; /* optional */
+	BIGNUM *pub_key;	/* g^x */
+	BIGNUM *priv_key;	/* x */
+
+	int flags;
+	BN_MONT_CTX *method_mont_p;
+	/* Place holders if we want to do X9.42 DH */
+	BIGNUM *q;
+	BIGNUM *j;
+	unsigned char *seed;
+	int seedlen;
+	BIGNUM *counter;
+
+	int references;
+	CRYPTO_EX_DATA ex_data;
+	const DH_METHOD *meth;
+	ENGINE *engine;
+	};
+#endif
+
 /** @brief Holds state information for encrypted peer communications */
 typedef struct
 {