diff --git a/lib_com/options.h b/lib_com/options.h
index 1226491d10e2f56176913942bc9e905ad1fde580..20886036b97437599f45881220e806264846fd5a 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -104,6 +104,7 @@
 #define NONBE_FIX_1261_MASA_EXT_META_JBM                /* Nokia: issue #1261: MASA metadata EXT output delay buffer init in JBM */
 #define NONBE_FIX_1143_MASA_BRSW                        /* Nok: Fix for issue 1143: MSAN use of uninitialized value in masa decoding to binaural with dtx bitrate switching and 5 % FER */
 #define NONBE_FIX_1220_OMASA_JBM_EXT_USAN               /* Nokia: fix issue 1220 OMASA EXT JBM USAN, also fix similar cases of free to avoid future problems */
+#define NONBE_FIX_1376_MDCT_CONCEALMENT                 /* FhG: fix concealment artifact in MDCT Stereo with DTX, in case transition frame gets lost */
 
 /* #################### End BASOP porting switches ############################ */
 
diff --git a/lib_dec/ivas_mdct_core_dec_fx.c b/lib_dec/ivas_mdct_core_dec_fx.c
index 4744a906dbc2ce05a0e9255ff305155008e2691c..532ab471864dc4bfb959f1ecff028b722888d565 100644
--- a/lib_dec/ivas_mdct_core_dec_fx.c
+++ b/lib_dec/ivas_mdct_core_dec_fx.c
@@ -1695,7 +1695,17 @@ void ivas_mdct_core_tns_ns_fx(
                 q_x = add( q_x, 1 );
             }
 
+#ifdef NONBE_FIX_1376_MDCT_CONCEALMENT
+            /*
+               2025-09-07, mul:
+               in case of PLC, applying SNS up to L_spec might not be enough: In case the transition frame from DTX after an inactive period is lost, L_spec is assumed to represent a regular TCX frame,
+               however, this frame is nevertheless acting as an transition frame as also visible in L_frameTCX; thus, the safer approach to prevent high frequency artifacts is to apply the SNS up to L_frameTCX;
+               in case this is not necessary, x[] is filled with zeros, and the multiplication is not causing any additional harm
+            */
+            v_multc_fixed( x_fx[ch][k] + st->hTcxCfg->psychParamsCurrent->nBins, sns_int_scf_fx[FDNS_NPTS - 1], x_fx[ch][k] + st->hTcxCfg->psychParamsCurrent->nBins, sub( s_max( L_spec[ch], L_frameTCX[ch] ), st->hTcxCfg->psychParamsCurrent->nBins ) );
+#else
             v_multc_fixed( x_fx[ch][k] + st->hTcxCfg->psychParamsCurrent->nBins, sns_int_scf_fx[FDNS_NPTS - 1], x_fx[ch][k] + st->hTcxCfg->psychParamsCurrent->nBins, sub( L_spec[ch], st->hTcxCfg->psychParamsCurrent->nBins ) );
+#endif
 
             q_2 = sub( add( q_x, q_sns_int_scf ), 31 );
             Scale_sig32( &x_fx[ch][k][0], st->hTcxCfg->psychParamsCurrent->nBins, sub( q_2, q_x ) );