diff --git a/lib_dec/fd_cng_dec.c b/lib_dec/fd_cng_dec.c
index 812356c565d177c648975ffd1a699ecb54b45590..fe0e21b3555778d967c6c75351c6fee2e4046f38 100644
--- a/lib_dec/fd_cng_dec.c
+++ b/lib_dec/fd_cng_dec.c
@@ -1244,7 +1244,7 @@ void generate_comfort_noise_dec_flt(
     SynthesisSTFT_flt( fftBuffer, timeDomainOutput, hFdCngCom->olapBufferSynth_flt, hFdCngCom->olapWinSyn_flt, tcx_transition, hFdCngCom, st->element_mode, nchan_out );
 #else
     Word32 fftBuffer_fx[FFTLEN], timeDomainBuffer_fx[L_FRAME16k];
-    Word16 exp = Q15;
+    Word16 exp = Q14;
     for ( i = 0; i < hFdCngCom->fftlen; i++ )
     {
         fftBuffer_fx[i] = float_to_fix( fftBuffer[i], exp );
diff --git a/lib_dec/ivas_decision_matrix_dec.c b/lib_dec/ivas_decision_matrix_dec.c
index 1a309f9b807fbd70d9165ce85eb8cbb8d66dd4c7..c90f6c1a3900c61c5efd7c0e3eba0604d7339de6 100644
--- a/lib_dec/ivas_decision_matrix_dec.c
+++ b/lib_dec/ivas_decision_matrix_dec.c
@@ -50,7 +50,7 @@
 #ifdef IVAS_FLOAT_FIXED
 static Word16 get_next_index_4_by_15[16] =
 {
-    0, 2184, 4369, 6553, 8738, 10922, 13107, 15291, 17476, 19660, 21845, 24029, 26214, 28398, 30583, 32768
+    0, 2184, 4369, 6553, 8738, 10922, 13107, 15291, 17476, 19660, 21845, 24029, 26214, 28398, 30583, 32767
 };
 #endif
 
@@ -547,7 +547,7 @@ void ivas_decision_matrix_dec_fx(
             st->hFdCngDec->hFdCngCom->coherence_fx = get_next_index_4_by_15[index];
 
             /* TODO: remove floating point dependency */
-            st->hFdCngDec->hFdCngCom->coherence_flt = get_next_index_4_by_15[index] / ( 1 << 15 );
+            st->hFdCngDec->hFdCngCom->coherence_flt = ( (float) get_next_index_4_by_15[index] ) / ( ( 1 << 15 ) - 1 );
 
             /* read flag for no side noise shape */
             st->hFdCngDec->hFdCngCom->no_side_flag = get_next_indice( st, 1 );