diff --git a/lib_com/options.h b/lib_com/options.h
index 458b1690dfbcfe18424b460508ce4ba05964da68..fe5c38761de177cd18f035750d67843b426e97cd 100755
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -171,7 +171,7 @@
 #define NONBE_FIX_1056_ISM_RATE_SWITCH                  /* FhG: Fix #1056: fix TC buffer udpate on a ISM rate switch */	
 #define NONBE_FIX_1075                                  /* FhG: fix segfault for bitrate switching + BINAURAL_ROOM_REVERB output in MC */
 #define NON_BE_FIX_1041_USE_OLD_CNG_LSPS_IF_NONSTAB     /* FhG: fix bug in TD MDCT-Stereo concealment */
-
+#define NONBE_FIX_1063_DIV_BY_ZERO_SUMNRG               /* VoiceAge: issue 1063: division by zero for angle_rot feature in the UNCLR classifier */
 /* #################### End BASOP porting switches ############################ */
 
 #endif
diff --git a/lib_dec/waveadjust_fec_dec_fx.c b/lib_dec/waveadjust_fec_dec_fx.c
index e0c599e235c098b8275f8bd8bcda333a9c2bb884..1b5b46d66e167a2729c068a6f16788938c4e82b8 100644
--- a/lib_dec/waveadjust_fec_dec_fx.c
+++ b/lib_dec/waveadjust_fec_dec_fx.c
@@ -916,7 +916,7 @@ void concealment_decode_fix(
     Word16 i;
     Word16 N = hPlcInfo->L_frameTCX;
     Word16 *seed = &( hPlcInfo->seed );
-    Word16 sign;
+    Word16 sign = 0;
     move16();
 
     IF( hPlcInfo->concealment_method == TCX_NONTONAL ) /* #define TCX_NONTONAL 0 */
diff --git a/lib_enc/ivas_stereo_dft_enc_itd_fx.c b/lib_enc/ivas_stereo_dft_enc_itd_fx.c
index 44434f78f6e060b8590e40f47e6f02c4de0ea724..373f4287ba0a60d36a6fe9615f63afe4970d228b 100644
--- a/lib_enc/ivas_stereo_dft_enc_itd_fx.c
+++ b/lib_enc/ivas_stereo_dft_enc_itd_fx.c
@@ -973,7 +973,10 @@ void stereo_dft_enc_compute_itd_fx(
 
     Word32 cng_xcorr_filt;
     Word16 cng_xcorr_filt_e;
-
+#ifdef NONBE_FIX_1063_DIV_BY_ZERO_SUMNRG
+    Word32 sum_nrg_delta;
+    Word16 sum_nrg_delta_e;
+#endif
     Word16 prev_itd_max;
     Word16 itd_max_flip;
 
@@ -1237,7 +1240,9 @@ void stereo_dft_enc_compute_itd_fx(
         move32();
         xcorr_abs[i] = Sqrt32( xcorr_abs[i], &xcorr_abs_e[i] );
         move32();
+#ifndef NONBE_FIX_1063_DIV_BY_ZERO_SUMNRG
         /* VM: prod_LL tends to overflow, better to replace with sum(log(prod_L)) and retrain the classifier */
+#endif
         prod_LL = prod_L;
         move32();
         prod_LL_e = prod_L_e;
@@ -1385,13 +1390,29 @@ void stereo_dft_enc_compute_itd_fx(
         hStereoClassif->xtalk_fv_fx[E_gainIPD] = L_shr_r( g_IPD, 10 ); // Q15
         move32();
 
+#ifdef NONBE_FIX_1063_DIV_BY_ZERO_SUMNRG
+        sum_nrg_delta = BASOP_Util_Add_Mant32Exp( sum_nrg_L, sum_nrg_L_e, L_negate( sum_nrg_R ), sum_nrg_R_e, &sum_nrg_delta_e );
+        IF( GE_32( sum_nrg_delta, 0 ) )
+        {
+            sum_nrg_delta = L_max( sum_nrg_delta, L_shl_sat( 1, sum_nrg_delta_e ) );
+        }
+        ELSE
+        {
+            sum_nrg_delta = L_min( sum_nrg_delta, L_negate( L_shl_sat( 1, sum_nrg_delta_e ) ) );
+        }
+        // angle_rot = fabsf( atanf( 2.0f * ( grand_dot_prod_real ) / sum_nrg_delta ) );
+        L_temp2 = BASOP_Util_Divide3232_Scale_newton( grand_dot_prod_real, sum_nrg_delta, &L_temp2_e );
+        L_temp2_e = add( L_temp2_e, sub( add( grand_dot_prod_real_e, 1 ), sum_nrg_delta_e ) );
+        angle_rot = L_abs( BASOP_util_atan( L_shr_r_sat( L_temp2, ( sub( 6, L_temp2_e ) ) ) ) ); // Q14
+#else
         // angle_rot = fabsf( atanf( 2.0f * ( grand_dot_prod_real ) / ( sum_nrg_L - sum_nrg_R + 1.0f ) ) );
         L_temp = BASOP_Util_Add_Mant32Exp( sum_nrg_L, sum_nrg_L_e, L_negate( sum_nrg_R ), sum_nrg_R_e, &L_temp_e );
         L_temp = BASOP_Util_Add_Mant32Exp( L_temp, L_temp_e, MAX_32, 0, &L_temp_e );
         L_temp2 = BASOP_Util_Divide3232_Scale_newton( grand_dot_prod_real, L_temp, &L_temp2_e );
         L_temp2_e = add( L_temp2_e, sub( add( grand_dot_prod_real_e, 1 ), L_temp_e ) );
         angle_rot = L_abs( BASOP_util_atan( L_shr_r_sat( L_temp2, ( sub( 6, L_temp2_e ) ) ) ) ); // Q14
-        // angle_rot = L_abs( BASOP_util_atan2( grand_dot_prod_real, L_temp, sub( add( grand_dot_prod_real_e, 1 ), L_temp_e ) ) ); // Q13
+                                                                                                 // angle_rot = L_abs( BASOP_util_atan2( grand_dot_prod_real, L_temp, sub( add( grand_dot_prod_real_e, 1 ), L_temp_e ) ) ); // Q13
+#endif
 
         hStereoClassif->unclr_fv_fx[E_angle_rot] = L_shl( angle_rot, 1 ); // Q15
         move32();