diff --git a/lib_com/options.h b/lib_com/options.h
index cc9a0d7f87b76d61d1e418f056c120aaa06987af..1d498d32d22e67e3ae3c85b8cce3ec589fba08fd 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -93,6 +93,7 @@
 #define NONBE_FIX_ISSUE_2206_SWB_EXPERIMENT_FIX_2527    /* Fix crash from issue #2527 */
 #define FIX_FLOAT_1539_G192_FORMAT_SWITCH               /* VA/Nokia: reintroduce format switching for g192 bitstreams */
 #define HARMONIZE_2595_reconfig_decoder_LPD             /* FhG: Harmonize reconfig_decoder_LPD with its ivas derivate */
+#define HARMONIZE_2596_SetModeIndex                     /* FhG: Harmonize SetModeIndex with its ivas derivate */
 
 /* #################### End BE switches ################################## */
 
diff --git a/lib_com/prot_fx.h b/lib_com/prot_fx.h
index 55fbb9362a5afac17f73730ae9d73c4bab6987f9..056cba33b9d37452d383c03c0f6d70182e65eb40 100644
--- a/lib_com/prot_fx.h
+++ b/lib_com/prot_fx.h
@@ -9547,11 +9547,19 @@ void core_coder_mode_switch_ivas_fx(
 );
 
 
+#ifdef HARMONIZE_2596_SetModeIndex
+void SetModeIndex_fx(
+#else
 void SetModeIndex_ivas_fx(
+#endif
     Encoder_State *st,              /* i  : Encoder state                          */
     const Word32 last_total_brate,  /* i  : last total bitrate                     Q0*/
     const Word16 last_element_mode, /* i  : last IVAS element mode                 Q0*/
     const Word16 MCT_flag           /* i  : hMCT handle allocated (1) or not (0)   Q0*/
+#ifdef HARMONIZE_2596_SetModeIndex
+    ,
+    const Word16 shift
+#endif
 );
 
 void init_tcx_cfg_ivas_fx(
diff --git a/lib_enc/ivas_core_pre_proc_front_fx.c b/lib_enc/ivas_core_pre_proc_front_fx.c
index b90cdacc8b7dbe76ed0d3b6715b7e84e0666aae8..0cb69bfdec2075472ef8dee0efc065ccaf1b6b78 100644
--- a/lib_enc/ivas_core_pre_proc_front_fx.c
+++ b/lib_enc/ivas_core_pre_proc_front_fx.c
@@ -1501,7 +1501,11 @@ void pre_proc_front_ivas_fx(
             test();
             IF( EQ_32( ivas_format, SBA_FORMAT ) && st->core_brate != FRAME_NO_DATA && st->last_core_brate == FRAME_NO_DATA && st->sba_br_sw_while_no_data )
             {
+#ifdef HARMONIZE_2596_SetModeIndex
+                SetModeIndex_fx( st, L_mult0( st->bits_frame_nominal, FRAMES_PER_SEC ), element_mode, MCT_flag, 0 );
+#else
                 SetModeIndex_ivas_fx( st, L_mult0( st->bits_frame_nominal, FRAMES_PER_SEC ), element_mode, MCT_flag );
+#endif
 
                 st->sba_br_sw_while_no_data = 0;
                 move16();
diff --git a/lib_enc/ivas_core_pre_proc_fx.c b/lib_enc/ivas_core_pre_proc_fx.c
index cbb28d43cffcae7fe9dd9045d9626771dbe25e26..2ca70b60579a9bed9aadb50021c80466cd72ba5f 100644
--- a/lib_enc/ivas_core_pre_proc_fx.c
+++ b/lib_enc/ivas_core_pre_proc_fx.c
@@ -351,7 +351,11 @@ void pre_proc_ivas_fx(
         st->total_brate = L_mult0( st->bits_frame_nominal, FRAMES_PER_SEC ); /* Q0 */
         move32();
 
+#ifdef HARMONIZE_2596_SetModeIndex
+        SetModeIndex_fx( st, imult3216( st->last_bits_frame_nominal, FRAMES_PER_SEC ), last_element_mode, MCT_flag, 0 );
+#else
         SetModeIndex_ivas_fx( st, imult3216( st->last_bits_frame_nominal, FRAMES_PER_SEC ), last_element_mode, MCT_flag );
+#endif
 
         st->sr_core = getCoreSamplerateMode2( element_mode, st->total_brate, st->bwidth, st->flag_ACELP16k, st->rf_mode, st->is_ism_format ); /* Q0 */
         move16();
@@ -411,7 +415,12 @@ void pre_proc_ivas_fx(
     {
         IF( NE_32( st->core_brate, FRAME_NO_DATA ) )
         {
+
+#ifdef HARMONIZE_2596_SetModeIndex
+            SetModeIndex_fx( st, L_mult0( st->bits_frame_nominal, FRAMES_PER_SEC ), element_mode, MCT_flag, 0 );
+#else
             SetModeIndex_ivas_fx( st, L_mult0( st->bits_frame_nominal, FRAMES_PER_SEC ), element_mode, MCT_flag );
+#endif
         }
 
         test();
diff --git a/lib_enc/prot_fx_enc.h b/lib_enc/prot_fx_enc.h
index 675710bcb017ce3ecc67642aa3d2e7179b181db7..7b20bddd1f2a019ac237efbdb45e81be2b2d5d29 100644
--- a/lib_enc/prot_fx_enc.h
+++ b/lib_enc/prot_fx_enc.h
@@ -2672,12 +2672,14 @@ void spec_flatness_fx(
     Word16 sSFM[SFM_NUM]      /*(o) spectral flatness rate*/
 );
 
+#ifndef HARMONIZE_2596_SetModeIndex
 void SetModeIndex_fx(
     Encoder_State *st,
     Word32 last_total_brate,        /* Q0 */
     const Word16 last_element_mode, /* Q0 */
     const Word16 is_mct,            /* Q0 */
     const Word16 shift );
+#endif
 
 void MDCT_selector_fx(
     Encoder_State *st,          /* i/o: Encoder State           */
diff --git a/lib_enc/setmodeindex_fx.c b/lib_enc/setmodeindex_fx.c
index 6c34efb0f914e00a1d8ba810db6c4ab1fba7a964..7183e452f3448992a32f0f229399a1851f2f23d2 100644
--- a/lib_enc/setmodeindex_fx.c
+++ b/lib_enc/setmodeindex_fx.c
@@ -21,6 +21,7 @@
 
   ---------------------------------------------------------------------------*/
 
+#ifndef HARMONIZE_2596_SetModeIndex
 void SetModeIndex_fx(
     Encoder_State *st,
     Word32 last_total_brate,        /* Q0 */
@@ -56,13 +57,21 @@ void SetModeIndex_fx(
 
     return;
 }
+#endif
 
-
+#ifdef HARMONIZE_2596_SetModeIndex
+void SetModeIndex_fx(
+#else
 void SetModeIndex_ivas_fx(
+#endif
     Encoder_State *st,              /* i  : Encoder state                          */
     const Word32 last_total_brate,  /* i  : last total bitrate                     Q0*/
     const Word16 last_element_mode, /* i  : last IVAS element mode                 Q0*/
     const Word16 MCT_flag           /* i  : hMCT handle allocated (1) or not (0)   Q0*/
+#ifdef HARMONIZE_2596_SetModeIndex
+    ,
+    const Word16 shift
+#endif
 )
 {
     Word16 ini_frame_loc = st->ini_frame; // Q0
@@ -93,7 +102,18 @@ void SetModeIndex_ivas_fx(
         ( NE_16( st->rf_mode_last, st->rf_mode ) ) ||
         ( st->element_mode > EVS_MONO && st->ini_frame == 0 ) )
     {
-        core_coder_mode_switch_ivas_fx( st, last_total_brate, MCT_flag );
+#ifdef HARMONIZE_2596_SetModeIndex
+        IF( EQ_16( st->element_mode, EVS_MONO ) )
+        {
+            core_coder_mode_switch_fx( st, last_total_brate, MCT_flag, shift );
+        }
+        ELSE
+        {
+#endif
+            core_coder_mode_switch_ivas_fx( st, last_total_brate, MCT_flag );
+#ifdef HARMONIZE_2596_SetModeIndex
+        }
+#endif
     }
 
     st->ini_frame = ini_frame_loc; // Q0