diff --git a/vp9/encoder/vp9_encodeframe.c b/vp9/encoder/vp9_encodeframe.c
index 929722563790292e195c4d6ad516797faa4200bd..65b98edf58d23a41a4a2384a0e04ef55d74b9d13 100644
--- a/vp9/encoder/vp9_encodeframe.c
+++ b/vp9/encoder/vp9_encodeframe.c
@@ -1364,6 +1364,69 @@ static void set_fixed_partitioning(VP9_COMP *cpi, const TileInfo *const tile,
   }
 }
 
+static void constrain_copy_partitioning(VP9_COMP *const cpi,
+                                        const TileInfo *const tile,
+                                        MODE_INFO **mi_8x8,
+                                        MODE_INFO **prev_mi_8x8,
+                                        int mi_row, int mi_col,
+                                        BLOCK_SIZE bsize) {
+  VP9_COMMON *const cm = &cpi->common;
+  const int mis = cm->mi_stride;
+  const int row8x8_remaining = tile->mi_row_end - mi_row;
+  const int col8x8_remaining = tile->mi_col_end - mi_col;
+  MODE_INFO *const mi_upper_left = cm->mi + mi_row * mis + mi_col;
+  const int bh = num_8x8_blocks_high_lookup[bsize];
+  const int bw = num_8x8_blocks_wide_lookup[bsize];
+  int block_row, block_col;
+
+  assert((row8x8_remaining > 0) && (col8x8_remaining > 0));
+
+  // If the SB64 if it is all "in image".
+  if ((col8x8_remaining >= MI_BLOCK_SIZE) &&
+      (row8x8_remaining >= MI_BLOCK_SIZE)) {
+    for (block_row = 0; block_row < MI_BLOCK_SIZE; block_row += bh) {
+      for (block_col = 0; block_col < MI_BLOCK_SIZE; block_col += bw) {
+        const int index = block_row * mis + block_col;
+        MODE_INFO *prev_mi = prev_mi_8x8[index];
+        const BLOCK_SIZE sb_type = prev_mi ? prev_mi->mbmi.sb_type : 0;
+        // Use previous partition if block size is not larger than bsize.
+        if (prev_mi && sb_type <= bsize) {
+          int block_row2, block_col2;
+          for (block_row2 = 0; block_row2 < bh; ++block_row2) {
+            for (block_col2 = 0; block_col2 < bw; ++block_col2) {
+              const int index2 = (block_row + block_row2) * mis +
+                  block_col + block_col2;
+              prev_mi = prev_mi_8x8[index2];
+              if (prev_mi) {
+                const ptrdiff_t offset = prev_mi - cm->prev_mi;
+                mi_8x8[index2] = cm->mi + offset;
+                mi_8x8[index2]->mbmi.sb_type = prev_mi->mbmi.sb_type;
+              }
+            }
+          }
+        } else {
+          // Otherwise, use fixed partition of size bsize.
+          mi_8x8[index] = mi_upper_left + index;
+          mi_8x8[index]->mbmi.sb_type = bsize;
+        }
+      }
+    }
+  } else {
+    // Else this is a partial SB64, copy previous partition.
+    for (block_row = 0; block_row < 8; ++block_row) {
+      for (block_col = 0; block_col < 8; ++block_col) {
+        MODE_INFO *const prev_mi = prev_mi_8x8[block_row * mis + block_col];
+        const BLOCK_SIZE sb_type = prev_mi ? prev_mi->mbmi.sb_type : 0;
+        if (prev_mi) {
+          const ptrdiff_t offset = prev_mi - cm->prev_mi;
+          mi_8x8[block_row * mis + block_col] = cm->mi + offset;
+          mi_8x8[block_row * mis + block_col]->mbmi.sb_type = sb_type;
+        }
+      }
+    }
+  }
+}
+
 static void copy_partitioning(VP9_COMMON *cm, MODE_INFO **mi_8x8,
                               MODE_INFO **prev_mi_8x8) {
   const int mis = cm->mi_stride;
@@ -2372,7 +2435,12 @@ static void encode_rd_sb_row(VP9_COMP *cpi, const TileInfo *const tile,
           rd_pick_partition(cpi, tile, tp, mi_row, mi_col, BLOCK_64X64,
                             &dummy_rate, &dummy_dist, 1, INT64_MAX);
         } else {
-          copy_partitioning(cm, mi_8x8, prev_mi_8x8);
+          if (sf->constrain_copy_partition &&
+              sb_has_motion(cm, prev_mi_8x8))
+            constrain_copy_partitioning(cpi, tile, mi_8x8, prev_mi_8x8,
+                                        mi_row, mi_col, BLOCK_16X16);
+          else
+            copy_partitioning(cm, mi_8x8, prev_mi_8x8);
           rd_use_partition(cpi, tile, mi_8x8, tp, mi_row, mi_col, BLOCK_64X64,
                            &dummy_rate, &dummy_dist, 1);
         }
diff --git a/vp9/encoder/vp9_speed_features.c b/vp9/encoder/vp9_speed_features.c
index b79e15979b9a62343d8a54f5f830ca039907e63e..c72b62bc5aa57d6ec0da1ac11719bf478b5d8162 100644
--- a/vp9/encoder/vp9_speed_features.c
+++ b/vp9/encoder/vp9_speed_features.c
@@ -209,6 +209,7 @@ static void set_rt_speed_feature(VP9_COMMON *cm, SPEED_FEATURES *sf,
     sf->use_square_partition_only = 1;
     sf->disable_filter_search_var_thresh = 100;
     sf->use_lastframe_partitioning = LAST_FRAME_PARTITION_ALL;
+    sf->constrain_copy_partition = 1;
     sf->use_uv_intra_rd_estimate = 1;
     sf->skip_encode_sb = 1;
     sf->subpel_iters_per_step = 1;
@@ -310,6 +311,7 @@ void vp9_set_speed_features(VP9_COMP *cpi) {
   sf->min_partition_size = BLOCK_4X4;
   sf->adjust_partitioning_from_last_frame = 0;
   sf->last_partitioning_redo_frequency = 4;
+  sf->constrain_copy_partition = 0;
   sf->disable_split_mask = 0;
   sf->mode_search_skip_flags = 0;
   sf->force_frame_boost = 0;
diff --git a/vp9/encoder/vp9_speed_features.h b/vp9/encoder/vp9_speed_features.h
index 922f8803e30abfb76a71cd91df5c2b4477cf0894..aaeb079cf9316f937569a9151c9c2991e1389331 100644
--- a/vp9/encoder/vp9_speed_features.h
+++ b/vp9/encoder/vp9_speed_features.h
@@ -245,6 +245,12 @@ typedef struct {
   // use_lastframe_partitioning is set.
   int last_partitioning_redo_frequency;
 
+  // This enables constrained copy partitioning, which, given an input block
+  // size bsize, will copy previous partition for partitions less than bsize,
+  // otherwise bsize partition is used. bsize is currently set to 16x16.
+  // Used for the case where motion is detected in superblock.
+  int constrain_copy_partition;
+
   // Disables sub 8x8 blocksizes in different scenarios: Choices are to disable
   // it always, to allow it for only Last frame and Intra, disable it for all
   // inter modes or to enable it always.