diff --git a/lib_com/options.h b/lib_com/options.h
index 9d69888ae722f1054725101db769ab6563c87906..f4c1a91f97c30d07a0c639ac0bb4f1e083d18bdc 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -125,4 +125,5 @@
 #define FIX_ISSUE_1186                          /* Ittiam: Fix for Issue 1186: Energy/scaling issue for ISM-1 at all bitrates */
 #define FIX_ISSUE_1165                          /* Ittiam: Fix for issue 1165: Assertion in lpc2lsp_fx for OMASA LTV input */
 #define FIX_ISSUE_1185                          /* Ittiam: Fix for issue 1185: Assertion in ivas_dirac_dec_binaural_internal_fx() for crash in decoder in fft30_with_cmplx_data()*/
+#define FIX_ISSUE_1209                          /* Ittiam: Fix for issue 1209: Assertion exit in BASOP encoder (stereo_dmx_evs)*/
 #endif
diff --git a/lib_enc/energy_fx.c b/lib_enc/energy_fx.c
index 2415ed287d1551c320f219bc7ebb0e70cda322f1..6d81eb82a7b8bd9dfe8261486ebf6330f1bdefbb 100644
--- a/lib_enc/energy_fx.c
+++ b/lib_enc/energy_fx.c
@@ -451,7 +451,11 @@ void background_update_fx(
             tmp = L_shr( 2147 /* 0.000001 Q31 */, sub( 31, scale_sb_energy ) ); /* scale_sb_energy */
             FOR( i = 0; i < SNR_sb_num; i++ )
             {
+#ifdef FIX_ISSUE_1209
+                sb_bg_energy[i] = L_add_sat( MUL_F( sb_bg_energy[i], 32112 /* 0.98 Q15 */ ), tmp ); /* scale_sb_energy */
+#else
                 sb_bg_energy[i] = L_add( MUL_F( sb_bg_energy[i], 32112 /* 0.98 Q15 */ ), tmp ); /* scale_sb_energy */
+#endif
                 move32();
             }
         }
diff --git a/lib_enc/spec_flatness_fx.c b/lib_enc/spec_flatness_fx.c
index a495ad681743bb6d4a0dd2a7caa9bb37f43c0abd..c2451886dac977208e677dc5ca833459b53afa5e 100644
--- a/lib_enc/spec_flatness_fx.c
+++ b/lib_enc/spec_flatness_fx.c
@@ -221,7 +221,12 @@ void spec_flatness_fx(
     SFM_Qtmp = sub( SFM_Qtmp, SPEC_AMP_Q );
     SFM_Qtmp = sub( SFM_Qtmp, SFM_Q );
 
+#ifdef FIX_ISSUE_1209
+    sSFM[1] = add_sat( mult( sSFM[1], 0x6ccc ), shr( mult( SFM, 0x1333 ), SFM_Qtmp ) );
+#else
     sSFM[1] = add( mult( sSFM[1], 0x6ccc ), shr( mult( SFM, 0x1333 ), SFM_Qtmp ) );
+#endif
+
     move16();
     /*sSFM3*/
     sums = 0;