diff --git a/lib_com/options.h b/lib_com/options.h
index c8740088c3757b7c65b709c1192b588320dfaa30..eab7ee2e60f8451aeb991346232be9968083c6da 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -153,6 +153,8 @@
 #define FIX_I173_I174                                   /* Issues 173 and 174: Remove frame and subframe index from ISm metadata and headtracking respectively. */
 #define FIX_TCX_DEC_RECONF_BFI
 #define FIX_SBA_DTX_DECODE_ERROR                        /* Issue 176: SBA decoder error with DTX at 80kbps SWB, Issue 21: SBA front-VAD threshold (203) */
+#define FIX_124_DONT_ALLOC_PLCINFO_IN_IVAS              /* Issue 124: do not allocate unused plc struct in IVAS modes which is only used in EVS mono */
+/*#define FIX_MCT_PLC_RECOVERY*/                            /* Issue 184: scale the old synthesis part correctly in the first good frame after lost frames in MCT modes - to be activated after previous switch is merged */
 #define FIX_MSAN_ERROR_STEREO_RATE_SWITCHING            /* addresses Issue 177 */
 #define SBA_BR_SWITCHING                                /* Issue 114: Changes for sba bit rate switching*/
 #define FIX_AGC_WINFUNC_MEMORY                          /* Issue 62: lower agc_com.winFunc memory consumption */
diff --git a/lib_dec/dec_tcx.c b/lib_dec/dec_tcx.c
index 904e1178513ab66c956966235378bf1642c585a0..20e4dedbe327dbbb2f9b22a6477c661995d0ae5d 100644
--- a/lib_dec/dec_tcx.c
+++ b/lib_dec/dec_tcx.c
@@ -152,7 +152,11 @@ void decoder_tcx_post(
     if ( bfi && !st->use_partial_copy )
     {
         /* run lpc gain compensation not for waveform adjustment */
+#ifdef FIX_124_DONT_ALLOC_PLCINFO_IN_IVAS
+        if ( !st->enablePlcWaveadjust || ( st->hPlcInfo != NULL && st->hPlcInfo->concealment_method == TCX_TONAL ) )
+#else
         if ( !st->enablePlcWaveadjust || st->hPlcInfo->concealment_method == TCX_TONAL )
+#endif
         {
             float gainHelperFB = hTcxDec->gainHelper;
             float stepCompensateFB = hTcxDec->stepCompensate * st->L_frame / hTcxDec->L_frameTCX;
diff --git a/lib_dec/init_dec.c b/lib_dec/init_dec.c
index 4f022e2811f7f65320fdd24964d493715f1473b4..4b74ccebb92a9bc0282d91c145f1da6bbd897144 100644
--- a/lib_dec/init_dec.c
+++ b/lib_dec/init_dec.c
@@ -661,7 +661,11 @@ ivas_error init_decoder(
      * Mode 2 initialization
      *-----------------------------------------------------------------*/
 
+#ifdef FIX_124_DONT_ALLOC_PLCINFO_IN_IVAS
+    if ( st->element_mode == EVS_MONO )
+#else
     if ( idchan == 0 && st->element_mode != IVAS_CPE_MDCT )
+#endif
     {
         if ( ( st->hPlcInfo = (T_PLCInfo_HANDLE) count_malloc( sizeof( T_PLCInfo ) ) ) == NULL )
         {
@@ -685,8 +689,9 @@ ivas_error init_decoder(
         st->hTECDec = NULL;
     }
 
+#ifndef FIX_124_DONT_ALLOC_PLCINFO_IN_IVAS // the initialziation is done in open_decoder_LPD()
     st->enablePlcWaveadjust = 0;
-
+#endif
     /* Init Core Decoder */
     open_decoder_LPD( st, st->total_brate, st->last_total_brate, st->bwidth, 0, st->element_mode, 1 );
 
diff --git a/lib_dec/ivas_core_dec.c b/lib_dec/ivas_core_dec.c
index e18f0e3e5db2f8bb869ac20949eec75cf949bb38..5c189b7d32d08ae33d4975fc180a3636198d1d8e 100644
--- a/lib_dec/ivas_core_dec.c
+++ b/lib_dec/ivas_core_dec.c
@@ -181,13 +181,32 @@ ivas_error ivas_core_dec(
             st->flagGuidedAcelp = 0;
         }
 
+#ifdef FIX_124_DONT_ALLOC_PLCINFO_IN_IVAS
+#ifdef FIX_MCT_PLC_RECOVERY
+        if ( !st->bfi && st->prev_bfi && ( st->last_core_bfi == TCX_20_CORE || st->last_core_bfi == TCX_10_CORE ) && st->hTcxDec != NULL )
+#else
+        if ( !st->bfi && st->prev_bfi && ( st->last_core_bfi == TCX_20_CORE || st->last_core_bfi == TCX_10_CORE ) && st->hTcxDec != NULL && hMCT == NULL )
+#endif
+        {
+            float gain;
+
+            gain = st->hTcxDec->conceal_eof_gain * st->last_concealed_gain_syn_deemph;
+            v_multc( st->hHQ_core->old_out, gain, st->hHQ_core->old_out, st->hTcxDec->L_frameTCX );
+            v_multc( st->hHQ_core->old_outLB, gain, st->hHQ_core->old_outLB, st->L_frame );
+
+            if ( !st->hTcxCfg->last_aldo )
+            {
+                v_multc( st->hTcxDec->syn_OverlFB, gain, st->hTcxDec->syn_OverlFB, st->hTcxCfg->tcx_mdct_window_lengthFB );
+                v_multc( st->hTcxDec->syn_Overl, gain, st->hTcxDec->syn_Overl, st->hTcxCfg->tcx_mdct_window_length );
+            }
+        }
+#else
         /* PLC: [TCX: Fade-out-recovery] - overlapping part needs to be attenuated for first good frame */
         if ( !st->bfi && st->prev_bfi && ( st->last_core_bfi == TCX_20_CORE || st->last_core_bfi == TCX_10_CORE ) )
         {
             float gain;
 
-            gain = ( st->element_mode == IVAS_CPE_MDCT ) ? st->hTcxDec->conceal_eof_gain : ( st->hPlcInfo != NULL ) ? st->hPlcInfo->recovery_gain
-                                                                                                                    : 0.0f;
+            gain = ( st->element_mode == IVAS_CPE_MDCT ) ? st->hTcxDec->conceal_eof_gain : ( st->hPlcInfo != NULL ) ? st->hPlcInfo->recovery_gain : 0.0f;
 
             if ( ( st->element_mode == IVAS_CPE_MDCT && hMCT == NULL ) || ( st->hPlcInfo != NULL ) )
             {
@@ -201,6 +220,7 @@ ivas_error ivas_core_dec(
                 }
             }
         }
+#endif
 
         set_f( voice_factors[n], 0.f, NB_SUBFR16k );
         set_f( hb_synth[n], 0.0f, L_FRAME48k );