diff --git a/server/modules/routing/readwritesplit/rwsplit_route_stmt.cc b/server/modules/routing/readwritesplit/rwsplit_route_stmt.cc
index 58d2e0b16..9cf22957e 100644
--- a/server/modules/routing/readwritesplit/rwsplit_route_stmt.cc
+++ b/server/modules/routing/readwritesplit/rwsplit_route_stmt.cc
@@ -51,7 +51,7 @@ void RWSplitSession::handle_connection_keepalive(RWBackend* target)
             if (backend->in_use() && backend != target && !backend->is_waiting_result())
             {
                 MXB_AT_DEBUG(nserv++);
-                int64_t diff = now - backend->dcb()->last_read;
+                int64_t diff = now - std::max(backend->dcb()->last_read, backend->dcb()->last_write);
 
                 if (diff > keepalive)
                 {