diff --git a/src/libslic3r/PrintApply.cpp b/src/libslic3r/PrintApply.cpp
index 39d5716b08..53f93f5b69 100644
--- a/src/libslic3r/PrintApply.cpp
+++ b/src/libslic3r/PrintApply.cpp
@@ -1916,6 +1916,12 @@ Print::ApplyStatus Print::apply(const Model &model, DynamicPrintConfig new_full_
                 }
 			if (new_objects || deleted_objects)
                 update_apply_status(this->invalidate_steps({ psSkirtBrim, psWipeTower, psGCodeExport }));
+            // A belt brim is clipped against the other objects on the plate (BeltBrim.cpp,
+            // belt_brim_obstacles), and it is rebuilt with its object's support step: an
+            // object that arrived or left changes every other object's brim.
+            if ((new_objects || deleted_objects) && m_config.belt_printer.value)
+                for (PrintObject *object : m_objects)
+                    update_apply_status(object->invalidate_step(posSupportMaterial));
 			if (new_objects)
 	            update_apply_status(false);
             print_regions_reshuffled = true;
@@ -1930,9 +1936,9 @@ Print::ApplyStatus Print::apply(const Model &model, DynamicPrintConfig new_full_
             }
         }
 
-        // Belt printer global mode: when any object's instances shifted,
-        // recompute m_belt_global_z_offset for ALL objects (it depends on
-        // min_shift across all objects, so one move affects everyone).
+        // Belt printer: when any object's instances shifted, re-slice every object.
+        // The global Z offset follows each object's position along the belt, and the
+        // belt brims are clipped against the other objects.
         if (belt_instances_shifted && m_config.belt_printer.value) {
             for (PrintObject *object : m_objects)
                 update_apply_status(object->invalidate_step(posSlice));