diff --git a/src/context.c b/src/context.c
index 3892f1b3..630e61d7 100644
--- a/src/context.c
+++ b/src/context.c
@@ -211,13 +211,13 @@ static const uint8_t INIT_GTX_FLAG[4][3][21] =
   }
 };
 
-static const uint8_t INIT_LAST[3][30] = {
-  { 125,  110,  124,  110,   95,   94,  125,  111,  111,   79,  125,  126,  111,  111,   79,
-    108,  123,   93,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU  },
-  { 125,  110,   94,  110,   95,   79,  125,  111,  110,   78,  110,  111,  111,   95,   94,
-    108,  123,  108,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU  },
-  { 110,  110,  124,  125,  140,  153,  125,  127,  140,  109,  111,  143,  127,  111,   79,
-    108,  123,   63,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU  },
+static const uint8_t INIT_LAST[3][38] = {
+  { 125,  110,  124,  110,   95,   94,  125,  111,  111,   79,  125,  126,  111,  111,   79,  126,  111,  111,  79,
+    108,  123,   93,  154,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU },
+  { 125,  110,   94,  110,   95,   79,  125,  111,  110,   78,  110,  111,  111,   95,   94,  111,  111,   95,   94,
+    108,  123,  108,  154,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU },
+  { 110,  110,  124,  125,  140,  153,  125,  127,  140,  109,  111,  143,  127,  111,   79,  143,  127,  111,   79,
+    108,  123,   63,  154,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU,  CNU },
 };
 
 static const uint8_t INIT_TRANSFORMSKIP_FLAG[3][2] =
@@ -324,12 +324,12 @@ void kvz_init_contexts(encoder_state_t *state, int8_t QP, int8_t slice)
     kvz_ctx_init(&cabac->ctx.inter_dir[i], QP, INIT_INTER_DIR[slice][i]);
   }
 
-  for (i = 0; i < 15; i++) {
+  for (i = 0; i < 19; i++) {
     kvz_ctx_init(&cabac->ctx.cu_ctx_last_y_luma[i], QP, INIT_LAST[slice][i] );
     kvz_ctx_init(&cabac->ctx.cu_ctx_last_x_luma[i], QP, INIT_LAST[slice][i] );
 
-    kvz_ctx_init(&cabac->ctx.cu_ctx_last_y_chroma[i], QP, INIT_LAST[slice][i+15] );
-    kvz_ctx_init(&cabac->ctx.cu_ctx_last_x_chroma[i], QP, INIT_LAST[slice][i+15] );
+    kvz_ctx_init(&cabac->ctx.cu_ctx_last_y_chroma[i], QP, INIT_LAST[slice][i+19] );
+    kvz_ctx_init(&cabac->ctx.cu_ctx_last_x_chroma[i], QP, INIT_LAST[slice][i+19] );
 
   }
 
diff --git a/src/encoderstate.h b/src/encoderstate.h
index 6ea5e28e..38308f2e 100644
--- a/src/encoderstate.h
+++ b/src/encoderstate.h
@@ -342,11 +342,20 @@ static INLINE bool is_last_cu_in_qg(const encoder_state_t *state, int x, int y,
 }
 
 
-static const uint8_t g_group_idx[32] = {
+static const uint8_t g_group_idx[128] = {
   0, 1, 2, 3, 4, 4, 5, 5, 6, 6,
   6, 6, 7, 7, 7, 7, 8, 8, 8, 8,
   8, 8, 8, 8, 9, 9, 9, 9, 9, 9,
-  9, 9 };
+  9, 9,10,10,10,10,10,10,10,10,
+ 10,10,10,10,10,10,10,10,11,11,
+ 11,11,11,11,11,11,11,11,11,11,
+ 11,11,11,11,12,12,12,12,12,12,
+ 12,12,12,12,12,12,12,12,12,12,
+ 12,12,12,12,12,12,12,12,12,12,
+ 12,12,12,12,12,12,13,13,13,13,
+ 13,13,13,13,13,13,13,13,13,13,
+ 13,13,13,13,13,13,13,13,13,13,
+ 13,13,13,13,13,13,13,13 };
 
 static const uint8_t g_min_in_group[10] = {
   0, 1, 2, 3, 4, 6, 8, 12, 16, 24 };