diff --git a/include/cuframes_composer/cpp/camera_cell.hpp b/include/cuframes_composer/cpp/camera_cell.hpp
index 47685ab..42f18b6 100644
--- a/include/cuframes_composer/cpp/camera_cell.hpp
+++ b/include/cuframes_composer/cpp/camera_cell.hpp
@@ -17,21 +17,25 @@
 #include "../source.h"
 #include "cell.hpp"
 
+#include <string>
+
 namespace cfc {
 
 class CameraCell : public Cell {
 public:
-    CameraCell(const Rect& geom, cfc_source_t* source)
-        : Cell(geom), source_(source) {}
+    CameraCell(const Rect& geom, cfc_source_t* source, std::string source_key = {})
+        : Cell(geom), source_(source), source_key_(std::move(source_key)) {}
 
     void set_source(cfc_source_t* src) noexcept { source_ = src; }
     cfc_source_t* source() const noexcept { return source_; }
+    const std::string& source_key() const noexcept { return source_key_; }
 
 protected:
     void draw_content(CUstream stream, NV12Ref& dst) override;
 
 private:
     cfc_source_t* source_;            /* non-owning — pool владеет */
+    std::string source_key_;
 };
 
 } // namespace cfc
diff --git a/include/cuframes_composer/cpp/layout.hpp b/include/cuframes_composer/cpp/layout.hpp
index 75fcbc3..4148f2d 100644
--- a/include/cuframes_composer/cpp/layout.hpp
+++ b/include/cuframes_composer/cpp/layout.hpp
@@ -47,6 +47,11 @@ public:
     const std::string& name() const noexcept { return current_name_; }
     int cell_count() const noexcept { return static_cast<int>(cells_.size()); }
 
+    /* Найти текущий pixel-rect для камеры с заданным cuframes-key. NULL
+     * если этой камеры в layout сейчас нет. Используется detbox-overlay'ями
+     * для пересчёта bbox при смене layout. */
+    const Rect* find_camera_cell_rect(const std::string& source_key) const;
+
 private:
     std::vector<std::unique_ptr<Cell>> cells_;
     std::string current_name_;
diff --git a/include/cuframes_composer/cpp/source_pool.hpp b/include/cuframes_composer/cpp/source_pool.hpp
index 05bb24d..44daa7c 100644
--- a/include/cuframes_composer/cpp/source_pool.hpp
+++ b/include/cuframes_composer/cpp/source_pool.hpp
@@ -73,6 +73,7 @@ public:
     int size() const { return static_cast<int>(entries_.size()); }
     PoolEntry* by_index(int i) { return i >= 0 && i < size() ? entries_[i].get() : nullptr; }
     PoolEntry* by_key(const std::string& key);
+    PoolEntry* by_frigate_camera(const std::string& frigate_camera);
 
     /* Уведомить о motion (вызывается из Frigate MQTT subscriber'а через
      * C-shim). Если zone-filter задан — проверяет пересечение. */
diff --git a/include/cuframes_composer/overlay.h b/include/cuframes_composer/overlay.h
index 3f74584..a67554d 100644
--- a/include/cuframes_composer/overlay.h
+++ b/include/cuframes_composer/overlay.h
@@ -176,6 +176,13 @@ int cfc_overlay_create_detection_boxes(
  * правильный overlay по incoming event'у. */
 const char *cfc_overlay_detbox_camera_key(cfc_overlay_t *ov);
 
+/* Обновить cell-геометрию runtime (при смене layout композитора). Композитор
+ * вызывает перед draw каждым detbox-overlay'ем — пересчитывает положение
+ * рамки под текущую позицию камеры. */
+int cfc_overlay_detbox_set_cell_geom(cfc_overlay_t *ov,
+                                       int cell_x, int cell_y,
+                                       int cell_w, int cell_h);
+
 /* Проверить пересечение current_zones события с required_zones overlay'я.
  *   - если required_zones пуст → всегда 1 (filter off)
  *   - если current_zones пуст → 0 (объект вне зон)
diff --git a/src/cpp/composer.cpp b/src/cpp/composer.cpp
index 1f731df..5743994 100644
--- a/src/cpp/composer.cpp
+++ b/src/cpp/composer.cpp
@@ -362,6 +362,26 @@ NV12Ref Composer::compose_frame()
     /* Backward-compat overlays (CLI text/icon, detbox) — поверх Layout. */
     for (auto* ov : overlays_) {
         if (!ov) continue;
+
+        /* Detection box рисуется в координатах cell камеры. Cell может
+         * перемещаться по экрану при смене layout — синхронизируем cell-geom
+         * перед каждым draw. */
+        if (cfc_overlay_get_type(ov) == CFC_OVERLAY_DETECTION_BOXES) {
+            const char* fcam = cfc_overlay_detbox_camera_key(ov);
+            if (fcam) {
+                PoolEntry* e = pool_.by_frigate_camera(fcam);
+                if (e) {
+                    const Rect* r = layout_.find_camera_cell_rect(e->cuframes_key);
+                    if (r) {
+                        cfc_overlay_detbox_set_cell_geom(ov, r->x, r->y, r->w, r->h);
+                    } else {
+                        /* Камеры нет в текущем layout — скрываем рамки. */
+                        cfc_overlay_detbox_set_cell_geom(ov, 0, 0, 0, 0);
+                    }
+                }
+            }
+        }
+
         cfc_overlay_draw(ov, reinterpret_cast<CUstream>(stream_),
                           y, pitch_y_, uv, pitch_uv_,
                           cfg_.width, cfg_.height);
diff --git a/src/cpp/layout.cpp b/src/cpp/layout.cpp
index 493219c..046e847 100644
--- a/src/cpp/layout.cpp
+++ b/src/cpp/layout.cpp
@@ -45,7 +45,8 @@ void Layout::apply(const LayoutTemplate& tpl,
     for (std::size_t i = 0; i < camera_templates.size(); ++i) {
         Rect r = to_pixels(*camera_templates[i], frame_w, frame_h);
         if (i < active_sorted.size() && active_sorted[i] && active_sorted[i]->source) {
-            auto cell = std::make_unique<CameraCell>(r, active_sorted[i]->source);
+            auto cell = std::make_unique<CameraCell>(r, active_sorted[i]->source,
+                                                       active_sorted[i]->cuframes_key);
             cell->add_decoration(std::make_unique<BorderDecoration>(border_style));
             /* Label с именем камеры и приоритетом. */
             char label_buf[96];
@@ -79,4 +80,15 @@ void Layout::render(CUstream stream, NV12Ref& dst)
     for (auto& c : cells_) c->draw(stream, dst);
 }
 
+const Rect* Layout::find_camera_cell_rect(const std::string& source_key) const
+{
+    for (auto& c : cells_) {
+        auto* cc = dynamic_cast<const CameraCell*>(c.get());
+        if (cc && cc->source_key() == source_key) {
+            return &cc->geometry();
+        }
+    }
+    return nullptr;
+}
+
 } // namespace cfc
diff --git a/src/cpp/source_pool.cpp b/src/cpp/source_pool.cpp
index a458586..8169e1e 100644
--- a/src/cpp/source_pool.cpp
+++ b/src/cpp/source_pool.cpp
@@ -77,6 +77,14 @@ PoolEntry* SourcePool::by_key(const std::string& key)
     return nullptr;
 }
 
+PoolEntry* SourcePool::by_frigate_camera(const std::string& fcam)
+{
+    for (auto& e : entries_) {
+        if (e->frigate_camera == fcam) return e.get();
+    }
+    return nullptr;
+}
+
 void SourcePool::motion_pulse(const std::string& frigate_camera,
                                 const std::vector<std::string>& current_zones)
 {
diff --git a/src/overlay.c b/src/overlay.c
index 52a3d26..0a31771 100644
--- a/src/overlay.c
+++ b/src/overlay.c
@@ -647,6 +647,21 @@ const char *cfc_overlay_detbox_camera_key(cfc_overlay_t *ov)
     return ov->u.detbox.camera_key;
 }
 
+int cfc_overlay_detbox_set_cell_geom(cfc_overlay_t *ov,
+                                       int cell_x, int cell_y,
+                                       int cell_w, int cell_h)
+{
+    if (!ov || ov->type != CFC_OVERLAY_DETECTION_BOXES) return -1;
+    detbox_data_t *d = &ov->u.detbox;
+    pthread_mutex_lock(&d->mu);
+    d->cfg.cell_x = cell_x;
+    d->cfg.cell_y = cell_y;
+    d->cfg.cell_w = cell_w;
+    d->cfg.cell_h = cell_h;
+    pthread_mutex_unlock(&d->mu);
+    return 0;
+}
+
 int cfc_overlay_detbox_match_zones(cfc_overlay_t *ov,
                                      const char *const *current_zones,
                                      int n)