diff --git a/src/search.c b/src/search.c
index b7e23ddc..3d002cfa 100644
--- a/src/search.c
+++ b/src/search.c
@@ -318,13 +318,49 @@ static void search_inter(encoder_control *encoder, uint16_t x_ctb,
 
 }
 
+#define SUB_SCU_BIT_MASK (64 - 1)
+#define SUB_SCU(xy) (xy & SUB_SCU_BIT_MASK)
+#define LCU_CU_WIDTH 8
+#define LCU_T_CU_WIDTH 9
 
 /**
  * Copy all non-reference CU data from depth+1 to depth.
  */
-static void work_tree_copy_up(int x, int y, int depth, lcu_t work_tree[MAX_PU_DEPTH])
+static void work_tree_copy_up(int x_px, int y_px, int depth, lcu_t work_tree[MAX_PU_DEPTH])
 {
+  // Copy non-reference CUs.
+  {
+    const int x_cu = SUB_SCU(x_px) >> MAX_DEPTH;
+    const int y_cu = SUB_SCU(y_px) >> MAX_DEPTH;
+    const int width_cu = LCU_WIDTH >> MAX_DEPTH >> depth;
+    int x, y;
+    for (y = y_cu; y < y_cu + width_cu; ++y) {
+      for (x = x_cu; x < x_cu + width_cu; ++x) {
+        const cu_info *from_cu = &work_tree[depth + 1].cu[x + y * LCU_T_CU_WIDTH];
+        cu_info *to_cu = &work_tree[depth].cu[x + y * LCU_T_CU_WIDTH];
+        memcpy(to_cu, from_cu, sizeof(*to_cu));
+      }
+    }
+  }
 
+  // Copy reconstructed pixels.
+  {
+    const int x = SUB_SCU(x_px);
+    const int y = SUB_SCU(y_px);
+    const int width_px = LCU_WIDTH >> depth;
+    const int luma_index = x + y * LCU_WIDTH;
+    const int chroma_index = (x / 2) + (y / 2) * (LCU_WIDTH / 2);
+
+    lcu_yuv_t *from = &work_tree[depth + 1].rec;
+    lcu_yuv_t *to = &work_tree[depth].rec;
+
+    picture_blit_pixels(&from->y[luma_index], &to->y[luma_index],
+                        width_px, width_px, LCU_WIDTH, LCU_WIDTH);
+    picture_blit_pixels(&from->u[chroma_index], &to->u[chroma_index],
+                        width_px / 2, width_px / 2, LCU_WIDTH / 2, LCU_WIDTH / 2);
+    picture_blit_pixels(&from->v[chroma_index], &to->v[chroma_index],
+                        width_px / 2, width_px / 2, LCU_WIDTH / 2, LCU_WIDTH / 2);
+  }
 }