diff --git a/av1/encoder/rdopt.c b/av1/encoder/rdopt.c
index 7b24b32..f0137c8 100644
--- a/av1/encoder/rdopt.c
+++ b/av1/encoder/rdopt.c
@@ -1133,6 +1133,11 @@
                                TX_SIZE tx_size) {
   uint64_t sse;
   switch (tx_size) {
+#if CONFIG_CB4X4
+    case TX_2X2:
+      sse = aom_sum_squares_2d_i16_c(diff, diff_stride, tx_size_wide[tx_size]);
+      break;
+#endif
     case TX_4X8:
       sse = aom_sum_squares_2d_i16(diff, diff_stride, 4) +
             aom_sum_squares_2d_i16(diff + 4 * diff_stride, diff_stride, 4);