diff --git a/lib_com/options.h b/lib_com/options.h
index 355f7dc1babe3cc8ff0364d064bcf6cdb2c8b791..17347d0d930a1102894454b53231632dda6463f6 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -104,4 +104,10 @@
 
 /* clang-format on */
 
+/* #################### Start BASOP optimization switches ############################ */
+
+#define OPT_2181_MATRIX_TRANSP_1_MUL /* Dolby: Issue 2181, optimize matrixTransp1Mul_fx. */
+
+/* #################### End BASOP optimization switches ############################ */
+
 #endif
diff --git a/lib_dec/ivas_ism_metadata_dec_fx.c b/lib_dec/ivas_ism_metadata_dec_fx.c
index 1a29a7a2c4498c23f53ea075d02659144dd683c4..f48c79ea7ec3b75ef4e0103b91c279dbe5b77523 100644
--- a/lib_dec/ivas_ism_metadata_dec_fx.c
+++ b/lib_dec/ivas_ism_metadata_dec_fx.c
@@ -30,7 +30,6 @@
 
 *******************************************************************************************************/
 
-#include "move.h"
 #include <stdint.h>
 #include "options.h"
 #include "ivas_cnst.h"
@@ -40,6 +39,7 @@
 #include "ivas_stat_enc.h"
 #include <math.h>
 #include "wmc_auto.h"
+#include "move.h"
 #include "ivas_prot_fx.h"
 
 
diff --git a/lib_rend/ivas_dirac_dec_binaural_functions_fx.c b/lib_rend/ivas_dirac_dec_binaural_functions_fx.c
index c3e301530bf39704633ab6ba092f5c50e05da20c..f0ea0e1ca9bffa1f6668665af62477bb9616a3a3 100644
--- a/lib_rend/ivas_dirac_dec_binaural_functions_fx.c
+++ b/lib_rend/ivas_dirac_dec_binaural_functions_fx.c
@@ -3965,6 +3965,45 @@ static void matrixTransp1Mul_fx(
 
     Word64 tmp_outRe_fx[BINAURAL_CHANNELS][BINAURAL_CHANNELS];
     Word64 tmp_outIm_fx[BINAURAL_CHANNELS][BINAURAL_CHANNELS];
+#ifdef OPT_2181_MATRIX_TRANSP_1_MUL
+    Word64 tmp64;
+    Word16 common_lsh, q;
+    q = add( add( q_A, q_B ), 1 );
+    common_lsh = sub( 63, q );
+    move16();
+
+    FOR( chA = 0; chA < BINAURAL_CHANNELS; chA++ )
+    {
+        FOR( chB = 0; chB < BINAURAL_CHANNELS; chB++ )
+        {
+            tmp64 = W_mult_32_32( Are_fx[0][chA], Bre_fx[0][chB] );
+            tmp64 = W_mac_32_32( tmp64, Are_fx[1][chA], Bre_fx[1][chB] );
+            tmp64 = W_mac_32_32( tmp64, Aim_fx[0][chA], Bim_fx[0][chB] );
+            tmp_outRe_fx[chA][chB] = W_mac_32_32( tmp64, Aim_fx[1][chA], Bim_fx[1][chB] );
+            move64();
+            common_lsh = s_min( common_lsh, W_norm( tmp_outRe_fx[chA][chB] ) );
+
+            tmp64 = W_mult_32_32( Aim_fx[0][chA], Bre_fx[0][chB] );
+            tmp64 = W_mac_32_32( tmp64, Aim_fx[1][chA], Bre_fx[1][chB] );
+            tmp64 = W_mac_32_32( W_neg( tmp64 ), Are_fx[0][chA], Bim_fx[0][chB] );
+            tmp_outIm_fx[chA][chB] = W_mac_32_32( tmp64, Are_fx[1][chA], Bim_fx[1][chB] );
+            move64();
+            common_lsh = s_min( common_lsh, W_norm( tmp_outIm_fx[chA][chB] ) );
+        }
+    }
+    FOR( chA = 0; chA < BINAURAL_CHANNELS; chA++ )
+    {
+        FOR( chB = 0; chB < BINAURAL_CHANNELS; chB++ )
+        {
+            outRe_fx[chA][chB] = W_extract_h( W_shl( tmp_outRe_fx[chA][chB], common_lsh ) );
+            move32();
+            outIm_fx[chA][chB] = W_extract_h( W_shl( tmp_outIm_fx[chA][chB], common_lsh ) );
+            move32();
+        }
+    }
+    *q_out = sub( add( q, common_lsh ), 32 );
+    move16();
+#else
     Word16 q_tmp_outRe_fx[BINAURAL_CHANNELS][BINAURAL_CHANNELS];
     Word16 q_tmp_outIm_fx[BINAURAL_CHANNELS][BINAURAL_CHANNELS];
     Word64 tmp64_1, tmp64_2;
@@ -4011,6 +4050,7 @@ static void matrixTransp1Mul_fx(
     }
     *q_out = sub( q_common, 32 );
     move16();
+#endif
     if ( L_and( is_zero_arr( outRe_fx[0], size ), is_zero_arr( outIm_fx[0], size ) ) )
     {
         *q_out = Q31;