diff --git a/lib_dec/acelp_core_dec_ivas_fx.c b/lib_dec/acelp_core_dec_ivas_fx.c
index ef8670388ba9cb29199ca589b244e93c60934b6a..323f98f8e8cb189def50e1e70baec97490085abd 100644
--- a/lib_dec/acelp_core_dec_ivas_fx.c
+++ b/lib_dec/acelp_core_dec_ivas_fx.c
@@ -953,13 +953,14 @@ ivas_error acelp_core_dec_ivas_fx(
                 /* Prepare ACB memory from last HQ frame */
                 old_exc_s_fx = st->old_exc_fx + sub( L_EXC_MEM_DEC, st->L_frame );
                 tmpF_fx = *old_exc_s_fx;
-                st->mem_deemph_fx = old_exc_s_fx[sub( st->L_frame, 1 )];
+                st->mem_deemph_fx = shl_sat( old_exc_s_fx[sub( st->L_frame, 1 )], st->Q_syn ); /* Q0 -> Q_syn */
                 move16();
                 PREEMPH_FX( old_exc_s_fx, st->preemph_fac, L_FRAME16k, &tmpF_fx );
                 Copy( old_exc_s_fx + sub( st->L_frame, M ), st->mem_syn2_fx, M );
+                Scale_sig( st->mem_syn2_fx, M, st->Q_syn ); /* Q0 -> Q_syn */
                 Residu3_fx( Aq_fx, old_exc_s_fx, old_exc_fx + sub( L_EXC_MEM_DEC, st->L_frame ), st->L_frame, 0 );
 #ifdef FIX_737_HQ_ACELP_SWITCH_SCALING_ERROR
-                Scale_sig( old_exc_fx + sub( L_EXC_MEM_DEC, st->L_frame ), st->L_frame, st->Q_exc );
+                Scale_sig( old_exc_fx + sub( L_EXC_MEM_DEC, st->L_frame ), st->L_frame, st->Q_exc ); /* Q0 -> Q_exc */
 #endif
             }
             test();