diff --git a/src/libstrongswan/plugins/curve25519/curve25519_dh.c b/src/libstrongswan/plugins/curve25519/curve25519_dh.c
index f5deb2136..5d489d413 100644
--- a/src/libstrongswan/plugins/curve25519/curve25519_dh.c
+++ b/src/libstrongswan/plugins/curve25519/curve25519_dh.c
@@ -42,6 +42,11 @@ struct private_curve25519_dh_t {
 	 */
 	bool computed;
 
+	/**
+	 * Public key provided by peer
+	 */
+	u_char pubkey[CURVE25519_KEY_SIZE];
+
 	/**
 	 * Curve25519 backend
 	 */
@@ -78,11 +83,8 @@ METHOD(key_exchange_t, set_public_key, bool,
 {
 	if (value.len == CURVE25519_KEY_SIZE)
 	{
-		if (this->drv->curve25519(this->drv, value.ptr, this->shared))
-		{
-			this->computed = TRUE;
-			return TRUE;
-		}
+		memcpy(this->pubkey, value.ptr, value.len);
+		return TRUE;
 	}
 	return FALSE;
 }
@@ -114,10 +116,12 @@ METHOD(key_exchange_t, set_private_key, bool,
 METHOD(key_exchange_t, get_shared_secret, bool,
 	private_curve25519_dh_t *this, chunk_t *secret)
 {
-	if (!this->computed)
+	if (!this->computed &&
+		!this->drv->curve25519(this->drv, this->pubkey, this->shared))
 	{
 		return FALSE;
 	}
+	this->computed = TRUE;
 	*secret = chunk_clone(chunk_from_thing(this->shared));
 	return TRUE;
 }