diff --git a/lib_com/options.h b/lib_com/options.h
index 16d3ed49e08ddf5b2405b47361ec270a025e2b58..5971079660860676f3ab1b3a3a783961c4cc0327 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -167,6 +167,7 @@
 #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.c b/lib_dec/ivas_mdct_core_dec.c
index 29ca975ee0ed8edc1fac2d1d05c4a853fb9edfbe..507800a9efd867ff6165d7a48880f54f804a36e0 100644
--- a/lib_dec/ivas_mdct_core_dec.c
+++ b/lib_dec/ivas_mdct_core_dec.c
@@ -1116,7 +1116,17 @@ void ivas_mdct_core_tns_ns(
             decoder_tcx_tns( st, L_frame_global[ch], L_spec[ch], L_frame[ch], L_frameTCX[ch], &x[ch][k][0], fUseTns[ch][k], &tnsData[ch][k], bfi, k, 1 );
 
             sns_shape_spectrum( x[ch][k], st->hTcxCfg->psychParamsCurrent, &sns_int_scf[0], st->hTcxCfg->psychParamsCurrent->nBins );
+#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( x[ch][k] + st->hTcxCfg->psychParamsCurrent->nBins, sns_int_scf[FDNS_NPTS - 1], x[ch][k] + st->hTcxCfg->psychParamsCurrent->nBins, max( L_spec[ch], L_frameTCX[ch] ) - st->hTcxCfg->psychParamsCurrent->nBins );
+#else
             v_multc( x[ch][k] + st->hTcxCfg->psychParamsCurrent->nBins, sns_int_scf[FDNS_NPTS - 1], x[ch][k] + st->hTcxCfg->psychParamsCurrent->nBins, L_spec[ch] - st->hTcxCfg->psychParamsCurrent->nBins );
+#endif
 
             decoder_tcx_tns( st, L_frame_global[ch], L_spec[ch], L_frame[ch], L_frameTCX[ch], &x[ch][k][0], fUseTns[ch][k], &tnsData[ch][k], bfi, k, 0 );
         }