diff --git a/sbin/hastd/proto_socketpair.c b/sbin/hastd/proto_socketpair.c
index 0d040f39454..c0b41a46da3 100644
--- a/sbin/hastd/proto_socketpair.c
+++ b/sbin/hastd/proto_socketpair.c
@@ -140,6 +140,10 @@ sp_send(void *ctx, const unsigned char *data, size_t size)
 		abort();
 	}
 
+	/* Someone is just trying to decide about side. */
+	if (data == NULL)
+		return (0);
+
 	return (proto_common_send(fd, data, size));
 }
 
@@ -174,6 +178,10 @@ sp_recv(void *ctx, unsigned char *data, size_t size)
 		abort();
 	}
 
+	/* Someone is just trying to decide about side. */
+	if (data == NULL)
+		return (0);
+
 	return (proto_common_recv(fd, data, size));
 }