diff --git a/src/engine/engine_collision_convex.c b/src/engine/engine_collision_convex.c
index e74b29d3..ceba996b 100644
--- a/src/engine/engine_collision_convex.c
+++ b/src/engine/engine_collision_convex.c
@@ -219,11 +219,11 @@ void mjc_support(mjtNum res[3], mjCCDObj* obj, const mjtNum dir[3]) {
       vert_globalid = m->mesh_graph + graphadr + 2 + numvert;
       edge_localid = m->mesh_graph + graphadr + 2 + 2*numvert;
 
-      // init with first vertex in convex hull
-      ibest = 0;
-      tmp = local_dir[0] * (mjtNum)vertdata[3*vert_globalid[0]] +
-            local_dir[1] * (mjtNum)vertdata[3*vert_globalid[0]+1] +
-            local_dir[2] * (mjtNum)vertdata[3*vert_globalid[0]+2];
+      // init with first vertex in convex hull or warmstart
+      ibest = obj->meshindex < 0 ? 0 : obj->meshindex;
+      tmp = local_dir[0] * (mjtNum)vertdata[3*vert_globalid[ibest]+0] +
+            local_dir[1] * (mjtNum)vertdata[3*vert_globalid[ibest]+1] +
+            local_dir[2] * (mjtNum)vertdata[3*vert_globalid[ibest]+2];
 
       // hill-climb until no change
       change = 1;