diff --git a/lib_com/options.h b/lib_com/options.h
index 52357d6c25210c34323435d170e21d6ace5d3190..de4344132b5b5fe98aa4336bca04cfcc5bb27aef 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -157,6 +157,7 @@
 /*#define SPLIT_REND_WITH_HEAD_ROT  */                  /* Dlb,FhG: Split Rendering contributions 21 and 35 */
 
 #define FIX_1027_GSC_INT_OVERFLOW                       /* VA: issue 2207: overflow in GSC */
+#define FIX_1024_REMOVE_PARAMMC_MIXING_MAT              /* VA: issue 1024: remove unused function ivas_param_mc_get_mono_stereo_mixing_matrices() */
 
 /* #################### End BE switches ################################## */
 
diff --git a/lib_dec/ivas_mc_param_dec.c b/lib_dec/ivas_mc_param_dec.c
index 70f01eb927619225ace8f1522b0415eae1629ce6..3ac207849c2ad6c3739cdff1dad123c6ad71b5a4 100644
--- a/lib_dec/ivas_mc_param_dec.c
+++ b/lib_dec/ivas_mc_param_dec.c
@@ -88,8 +88,10 @@ static void ivas_param_mc_dequantize_cov( PARAM_MC_DEC_HANDLE hDirAC, float *ild
 
 static void ivas_param_mc_get_mixing_matrices( PARAM_MC_DEC_HANDLE hParamMC, IVAS_OUTPUT_SETUP *hSynthesisOutputSetup, float Cx_in[PARAM_MC_MAX_PARAMETER_BANDS][PARAM_MC_MAX_TRANSPORT_CHANS * PARAM_MC_MAX_TRANSPORT_CHANS], float *mixing_matrix[], float *mixing_matrix_res[], const int16_t nY_int, const PARAM_MC_SYNTHESIS_CONF synth_conf, const int16_t nX, const int16_t nY );
 
+#ifndef FIX_1024_REMOVE_PARAMMC_MIXING_MAT
 static void ivas_param_mc_get_mono_stereo_mixing_matrices( PARAM_MC_DEC_HANDLE hParamMC, float Cx_in[PARAM_MC_MAX_PARAMETER_BANDS][PARAM_MC_MAX_TRANSPORT_CHANS * PARAM_MC_MAX_TRANSPORT_CHANS], float *mixing_matrix[], float *mixing_matrix_res[], const int16_t nY_intern, const int16_t nX, const int16_t nY_cov );
 
+#endif
 static void param_mc_update_mixing_matrices( PARAM_MC_DEC_HANDLE hParamMC, float *mixing_matrix[], float *mixing_matrix_res[], const uint16_t nX, const uint16_t nY );
 
 static void ivas_param_mc_dec_compute_interpolator( const uint16_t bAttackPresent, const uint16_t attackPos, const uint16_t interp_length, float *interpolator );
@@ -1454,15 +1456,19 @@ void ivas_param_mc_dec_digest_tc(
     }
 
 
+#ifndef FIX_1024_REMOVE_PARAMMC_MIXING_MAT
     if ( hParamMC->synthesis_conf == PARAM_MC_SYNTH_MONO_STEREO )
     {
         ivas_param_mc_get_mono_stereo_mixing_matrices( hParamMC, cx, hParamMC->h_output_synthesis_cov_state.mixing_matrix, hParamMC->h_output_synthesis_cov_state.mixing_matrix_res, nchan_out_transport, nchan_transport, nchan_out_cov );
     }
     else
     {
+#endif
         /* generate mixing matrices */
         ivas_param_mc_get_mixing_matrices( hParamMC, hSynthesisOutputSetup, cx, hParamMC->h_output_synthesis_cov_state.mixing_matrix, hParamMC->h_output_synthesis_cov_state.mixing_matrix_res, nchan_out_transport, hParamMC->synthesis_conf, nchan_transport, nchan_out_cov );
+#ifndef FIX_1024_REMOVE_PARAMMC_MIXING_MAT
     }
+#endif
 
     pop_wmops();
 
@@ -2445,7 +2451,7 @@ static void ivas_param_mc_get_mixing_matrices(
     return;
 }
 
-
+#ifndef FIX_1024_REMOVE_PARAMMC_MIXING_MAT
 /*-------------------------------------------------------------------------
  * ivas_param_mc_get_mono_stereo_mixing_matrices()
  *
@@ -2566,7 +2572,7 @@ static void ivas_param_mc_get_mono_stereo_mixing_matrices(
 
     return;
 }
-
+#endif
 
 /*-------------------------------------------------------------------------
  * param_mc_update_mixing_matrices()
diff --git a/lib_dec/ivas_out_setup_conversion.c b/lib_dec/ivas_out_setup_conversion.c
index 75015f7aeb06f4ef8006039cf22af78862d5e076..b66e02e1eeb4b6a09c8eb2d0679a623507c36f80 100644
--- a/lib_dec/ivas_out_setup_conversion.c
+++ b/lib_dec/ivas_out_setup_conversion.c
@@ -973,7 +973,11 @@ void ivas_ls_setup_conversion_process_mdct_param_mc(
         set_zero( Nrqq, MAX_OUTPUT_CHANNELS );
         set_zero( target_ch_ener, MAX_OUTPUT_CHANNELS );
 
+#ifdef FIX_1024_REMOVE_PARAMMC_MIXING_MAT
+        /* Step 1.2, get target channel energies for the transported format, Nrqq calculation */
+#else
         /* Step 1.2, get target channel energies for the transported format as in ivas_param_mc_get_mono_stereo_mixing_matrices(), Nrqq calculation */
+#endif
         ild_q = hParamMC->icld_q + bandIdx * hParamMC->hMetadataPMC->ild_mapping_conf->ild_map_size_lfe;
 
         for ( chInIdx = 0; chInIdx < nchan_transport_format; chInIdx++ )
@@ -991,7 +995,11 @@ void ivas_ls_setup_conversion_process_mdct_param_mc(
             Nrqq[hParamMC->hMetadataPMC->ild_mapping_conf->ild_index[chInIdx]] = powf( 10.0f, ild_q[chInIdx] / 10.0f ) * hParamMC->hMetadataPMC->ild_factors[chInIdx] * ref_ener;
         }
 
+#ifdef FIX_1024_REMOVE_PARAMMC_MIXING_MAT
+        /* Step 1.3 get target Cy (with dmx matrix from CICPX to MONO/STEREO saved in hParamMC) */
+#else
         /* Step 1.3 get target Cy like in ivas_param_mc_get_mono_stereo_mixing_matrices() (with dmx matrix from CICPX to MONO/STEREO saved in hParamMC) */
+#endif
         for ( chOutIdx = 0; chOutIdx < nchan_out; chOutIdx++ )
         {
             for ( i = 0; i < nchan_transport_format; i++ )