diff --git a/lib_com/ivas_cnst.h b/lib_com/ivas_cnst.h
index 85d2fff74a2be52af26dfcad302625c452d345a2..60807f62cbb847157cf4d56de29a811cc1ad2c71 100755
--- a/lib_com/ivas_cnst.h
+++ b/lib_com/ivas_cnst.h
@@ -309,8 +309,12 @@ typedef enum
 #define MIN_BRATE_SWB_STEREO                    IVAS_13k2                   /* min. stereo bitrate where SWB is supported */
 #define MIN_BRATE_FB_STEREO                     IVAS_32k                    /* min. SCE and stereo bitrate where FB is supported */
 #ifdef ISM_FB
+#ifdef ISM_FB_16k4
+#define MIN_BRATE_FB_ISM                        16000                       /* min. SCE bitrate where FB is supported in ISM format */
+#else
 #define MIN_BRATE_FB_ISM                        24000                       /* min. SCE bitrate where FB is supported in ISM format */
 #endif
+#endif
 
 #define MIN_TDM_BRATE_WB_TBE_1k05               12000                       /* min. per channel bitrate where WB TBE @1.05 kbps is supported (0.35kbs at lower bitrates) */
 #define MIN_BRATE_WB_TBE_1k05                   9650                        /* min. per channel bitrate where WB TBE @1.05 kbps is supported (0.35kbs at lower bitrates) */
diff --git a/lib_com/options.h b/lib_com/options.h
index 68e40038025d149c5dd85f456e557d35d1dc1b9f..e4d3a06b589e5bc8982f4c9a738860aa0751817b 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -158,8 +158,10 @@
 #define FIX_UNCLR_ISSUE                                 /* VoiceAge: issue 574: Fix UNCLR mis-classifications in noisy speech stereo */
 #define FIX_TCX_LOWRATE_LIMITATION                      /* VA: issue 577: TCX bitrate limitation only when DEBUGGING is active */
 #define FIX_575_LOW_OVERLAP_PLC_RECOVERY                /* FhG: Issue 575 fix for PLC and transistion to TCX5*/
+#define ISM_FB_16k4                                     /* VA: Issue: 579: change BW from SWB to FB in NxISM conditions to match the EVS codec */
 #define FIX_580_PARAMMC_ENER_BURSTS                     /* FhG: issue 580: energy bursts due to ILD holding when energy relations change too much */
 
+
 /* ################## End DEVELOPMENT switches ######################### */
 /* clang-format on */
 
diff --git a/lib_dec/gs_dec.c b/lib_dec/gs_dec.c
index ff684b47d36375e0b6d28a53ba3622f007b53307..1244f977936891d9b449612dd6e93023a71c4fdb 100644
--- a/lib_dec/gs_dec.c
+++ b/lib_dec/gs_dec.c
@@ -104,7 +104,11 @@ void decod_audio(
     }
 
     /* safety check in case of bit errors */
+#ifdef ISM_FB_16k4
+    if ( st->GSC_noisy_speech && st->bwidth < SWB && st->GSC_IVAS_mode == 0 )
+#else
     if ( st->GSC_noisy_speech && st->bwidth != SWB && st->GSC_IVAS_mode == 0 )
+#endif
     {
         st->BER_detect = 1;
         st->GSC_noisy_speech = 0;