diff --git a/lib_com/cnst.h b/lib_com/cnst.h
index a5030ac9c98bb3bf1f430798afe117443c43918a..197fbd3c4a8d1fefce72a50844e2b639f7e82c7c 100644
--- a/lib_com/cnst.h
+++ b/lib_com/cnst.h
@@ -1536,6 +1536,7 @@ enum
 #define SHB_OVERLAP_LEN                     ( L_FRAME16k - L_SHB_LAHEAD ) / ( NUM_SHB_SUBFR - 1 )
 #define QUANT_DIST_INIT                     ( 10000000000.0f )      /* Quantiser search distance initialisation */
 #define HIBND_ACB_L_FAC                     5 / 2                   /* SHB Interpolation Factor */
+#define HIBND_ACB_L_FAC_Q1                  ( 5 )                   /* SHB Interpolation Factor Q1 */
 #define NUM_HILBERTS                        2
 #define HILBERT_ORDER1                      5
 #define HILBERT_ORDER2                      4
diff --git a/lib_com/options.h b/lib_com/options.h
index d6bbaf88a69b9efc91b235899b23992d49b2b11f..5f585d891b6ed69d3797361c653796787c3a3ae3 100755
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -155,6 +155,7 @@
 #define FIX_ISSUE_1214                          /* Ittiam: Fix for issue 1214: Energy leakage in IGF tiles for MDCT-stereo @64kbps SWB*/
 #define FIX_881_HILBERT_FILTER                  /* VA: improve the precision of the Hilbert filter to remove 2kHz unwanted tone */
 #define FIX_ISSUE_1245                          /* Ittiam: Fix for issue 1245: Basop Encoder: Audible noise for silent Stereo input DTX on @24.4 kbps, @32 kbps*/
+#define FIX_ISSUE_1291                          /* Ittiam: Wrong use of imult1616() in ACELP rescaling */
 #define FIX_920_IGF_INIT_ERROR                  /* FhG: issue 920: fix bitrate mismatch in initial IGF config to avoid error message in same cases */
 #define FIX_MINOR_SVD_WMOPS_MR1010X             /* FhG: Minor WMOPS tuning, bit-exact to previous version, saves about 8.2 WMOPS for MR1010 */
 #define SVD_WMOPS_OPT                           /* Ittiam : SVD related optimizations */
diff --git a/lib_dec/acelp_core_dec_ivas_fx.c b/lib_dec/acelp_core_dec_ivas_fx.c
index e52c52c7c916ed88e95fccfbf4200f24d0272dc5..165594e772b957ea9d0ffbf716e6701673b0e70d 100644
--- a/lib_dec/acelp_core_dec_ivas_fx.c
+++ b/lib_dec/acelp_core_dec_ivas_fx.c
@@ -748,7 +748,11 @@ ivas_error acelp_core_dec_ivas_fx(
             IF( st->hMusicPF && st->hGSCDec )
             {
                 Rescale_exc( st->hMusicPF->dct_post_old_exc_fx, exc_fx, bwe_exc_fx, st->hGSCDec->last_exc_dct_in_fx, st->L_frame,
+#ifdef FIX_ISSUE_1291
+                             shr( imult1616( st->L_frame, HIBND_ACB_L_FAC_Q1 ), 1 ), 0, &( st->Q_exc ), st->Q_subfr, NULL, 0, INACTIVE );
+#else
                              imult1616( st->L_frame, HIBND_ACB_L_FAC ), 0, &( st->Q_exc ), st->Q_subfr, NULL, 0, INACTIVE );
+#endif
             }
             IF( st->hPFstat != NULL )
             {