diff --git a/lib_dec/FEC_HQ_phase_ecu_fx.c b/lib_dec/FEC_HQ_phase_ecu_fx.c
index dd63b65087584ca8edf9ebc22ace10edb22c8074..34d01d7fe0ea41b37e77e9096bfc0ebedb3f5128 100644
--- a/lib_dec/FEC_HQ_phase_ecu_fx.c
+++ b/lib_dec/FEC_HQ_phase_ecu_fx.c
@@ -4595,11 +4595,11 @@ static void ivas_fec_noise_filling_fx(
     {
         L_tmp = L_mult( *sinq_tab, *sinq_tab ); /*Q30 */
         sinq_tab++;
-        q2 = round_fx( L_sub( 2147483647, L_tmp ) );          /*Q15 */
-        q1 = round_fx( L_tmp );                               /*Q15 */
-        L_tmp = L_mult( ( *pt1 ), q1 );                       /*Qsynth+16 */
-        L_tmp = L_mac( L_tmp, shr( *pt6++, Q_old_out ), q2 ); /*Qsynth+16 */
-        ( *pt1++ ) = round_fx( L_tmp );                       /*Qsynth */
+        q2 = round_fx( L_sub( 2147483647, L_tmp ) );                                          /*Q15 */
+        q1 = round_fx( L_tmp );                                                               /*Q15 */
+        L_tmp = L_mult( ( *pt1 ), q1 );                                                       /*Qsynth+16 */
+        L_tmp = L_add( L_tmp, L_shr( Mpy_32_16_1( L_deposit_h( *pt6++ ), q2 ), Q_old_out ) ); /*Qsynth+16 */
+        ( *pt1++ ) = round_fx( L_tmp );                                                       /*Qsynth */
         move16();
     }