diff --git a/src/engine/engine_vis_visualize.c b/src/engine/engine_vis_visualize.c
index d0da232a..abcf8f34 100644
--- a/src/engine/engine_vis_visualize.c
+++ b/src/engine/engine_vis_visualize.c
@@ -1728,7 +1728,7 @@ void mjv_addGeoms(const mjModel* m, mjData* d, const mjvOption* vopt,
   // spatial tendons
   objtype = mjOBJ_TENDON;
   category = mjCAT_DYNAMIC;
-  if (vopt->flags[mjVIS_TENDON] && (category & catmask)) {
+  if (vopt->flags[mjVIS_TENDON] && (category & catmask) && m->ntendon) {
     // mark actuated tendons
     mj_markStack(d);
     int* tendon_actuated = mjSTACKALLOC(d, m->ntendon, int);