diff --git a/lib_com/options.h b/lib_com/options.h
index ad7191a8f3604a5e353da790d674db4f22c5868c..9e9922fb4d3551ca7006c962ae0b838d75b90c59 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -159,6 +159,7 @@
 #define FIX_998_UNUSED_FUNCTION                         /* FhG: issue 998: delete unused funtion ivas_dirac_dec_get_response_split_order */ 
 #define FIX_1009_ISM_NONDIEGETIC_PANNING                /* FhG: issue #1009: use correct object buffer for ISM1 non-diegetic pan      */
 #define FIX_993_REMOVE_SBA_GET_ORDER                    /* VA: issue 993: remove unused function ivas_sba_get_order() */
+#define FIX_1002_DEC_PHASE_ECU_USAN_OF_PHASE            /* Eri: issue #1002, usan-value-out-of-range-for-int16, kept BE for PLC-conditions   */
 #define FIX_960_SYN_OUTPUT                              /* VA: issue 960: unused function syn_output() is removed */
 
 /* #################### End BE switches ################################## */
diff --git a/lib_dec/FEC_HQ_phase_ecu.c b/lib_dec/FEC_HQ_phase_ecu.c
index ea604ef7052569dfdc4a37130c04c2cd95515301..7deb7db6466b25d9d5878e1069c1f1b717379886 100644
--- a/lib_dec/FEC_HQ_phase_ecu.c
+++ b/lib_dec/FEC_HQ_phase_ecu.c
@@ -973,7 +973,6 @@ static void subst_spec(
     float alpha_local;
     float beta_local;
 
-
     sincos = sincos_t_ext + 128;
     Lprot = (int16_t) ( L_PROT32k * output_frame / 640 );
     Lprot_1 = 1.0f / Lprot;
@@ -1092,7 +1091,14 @@ static void subst_spec(
         }
 
         Xph = corr_phase[m];
+#ifdef FIX_1002_DEC_PHASE_ECU_USAN_OF_PHASE
+        /* extract fractional phase integer index in the range [0...1023] */
+        Xph_short = (int16_t) ( 0x000003ff & (int32_t) ( ( Xph * 512 ) / EVS_PI ) );
+#else
         Xph_short = (int16_t) ( ( (int32_t) ( Xph * 512 / EVS_PI ) ) % 32768 ) & 0x03ff;
+#endif
+
+
         if ( Xph_short >= 512 )
         {
             sin_F = -sincos_t_ext[Xph_short - 512];
@@ -1136,7 +1142,11 @@ static void subst_spec(
                     mag_chg_local *= 0.5f + ( 1.0f - ( 1.0f / PHASE_DITH ) * ph_dith ) * 0.5f;
                 }
 
+#ifdef FIX_1002_DEC_PHASE_ECU_USAN_OF_PHASE
+                Xph_short = (int16_t) ( ( (int32_t) ( ( Xph * 512 ) / EVS_PI ) ) & 0x000003ff );
+#else
                 Xph_short = (int16_t) ( Xph * 512 / EVS_PI ) & 0x03ff;
+#endif
 
                 if ( Xph_short >= 512 )
                 {