diff --git a/lib_com/options.h b/lib_com/options.h
index e628cf13df47edce08dc03fdac03c2c31a968cf5..8d4c9acae68bba138b3574df6f67388da2728ce4 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -103,6 +103,7 @@
 #define HARMONIZE_DCT                                   /* VA: removal of duplicated DCT functions */
 #define FIX_2489_HARMONIZE_FdCng_encodeSID              /* FhG: harmonize FdCng_encodeSID_fx() and FdCng_encodeSID_ivas_fx()  */
 #define FIX_1527_CMR_BITRATE_IDX                        /* Fix for incorrect bitrate idx packed in rtp CMR E-byte */
+#define FIX_2509_HARMONIZE_OPEN_DECODER_LPD             /* FhG: BASOP issue 2509: Avoid reading of unitialized st->hTcxCfg->psychParamsCurrent by harmonizing open_decoder_LPD*_fx() */
 
 /* #################### End BE switches ################################## */
 
diff --git a/lib_com/prot_fx.h b/lib_com/prot_fx.h
index 1df94661325ecfc10e10246218d3b7f577e5184d..08447ca59a1a9591b3f2ca1d0275d55a6fdafec8 100644
--- a/lib_com/prot_fx.h
+++ b/lib_com/prot_fx.h
@@ -7287,13 +7287,19 @@ ivas_error ppp_quarter_decoder_fx(
     DTFS_STRUCTURE PREV_CW_D_FX,      /* i  : Previous DTFS                                            */
     Decoder_State *st_fx );
 
+#ifndef FIX_2509_HARMONIZE_OPEN_DECODER_LPD
 void open_decoder_LPD_fx(
     Decoder_State *st,
     const Word32 total_brate, /* Q0 */
     const Word16 bwidth       /* Q0 */
 );
+#endif
 
+#ifdef FIX_2509_HARMONIZE_OPEN_DECODER_LPD
+void open_decoder_LPD_fx(
+#else
 void open_decoder_LPD_ivas_fx(
+#endif
     Decoder_State *st,              /* i/o: decoder state structure                     */
     const Word32 total_brate,       /* i  : total bitrate                             Q0*/
     const Word32 last_total_brate,  /* i  : last total bitrate                        Q0*/
diff --git a/lib_dec/core_dec_init_fx.c b/lib_dec/core_dec_init_fx.c
index dd3115fb709f0b1bcbdffa12ccfacdde208e166c..080c2c844083594382b11ce1cd4e9b98f81aa1ae 100644
--- a/lib_dec/core_dec_init_fx.c
+++ b/lib_dec/core_dec_init_fx.c
@@ -12,6 +12,7 @@
 #include "rom_com.h"
 #include "cnst.h" /* for MIN_CNG_LEV */
 
+#ifndef FIX_2509_HARMONIZE_OPEN_DECODER_LPD
 /*-----------------------------------------------------------------------*
  * open_decoder_LPD_fx()
  *
@@ -1005,6 +1006,7 @@ void open_decoder_LPD_fx(
     }
     return;
 }
+#endif
 
 void tcxltp_dec_init_fx(
     TCX_LTP_DEC_HANDLE hTcxLtpDec, /* Q0 */
@@ -1114,7 +1116,16 @@ void acelp_plc_mdct_transition_fx(
     return;
 }
 
+#ifdef FIX_2509_HARMONIZE_OPEN_DECODER_LPD
+/*-----------------------------------------------------------------------*
+ * open_decoder_LPD_fx()
+ *
+ * Initialization of state variables
+ *-----------------------------------------------------------------------*/
+void open_decoder_LPD_fx(
+#else
 void open_decoder_LPD_ivas_fx(
+#endif
     Decoder_State *st,              /* i/o: decoder state structure                     */
     const Word32 total_brate,       /* i  : total bitrate                             Q0*/
     const Word32 last_total_brate,  /* i  : last total bitrate                        Q0*/
diff --git a/lib_dec/core_dec_switch_fx.c b/lib_dec/core_dec_switch_fx.c
index 142609fff4505ab659dc70912ef87ecd305fabeb..671dfc433d65add4eeba7c45e4169fad1a3353ad 100644
--- a/lib_dec/core_dec_switch_fx.c
+++ b/lib_dec/core_dec_switch_fx.c
@@ -89,7 +89,21 @@ void mode_switch_decoder_LPD_fx(
     test();
     IF( NE_16( fscale, st->fscale ) || ( switchWB != 0 ) || ( bSwitchFromAmrwbIO != 0 ) || EQ_16( st->last_codec_mode, MODE1 ) || st->force_lpd_reset )
     {
+#ifdef FIX_2509_HARMONIZE_OPEN_DECODER_LPD
+        Word16 Q_syn_Overl_TDAC = 0, Q_fer_samples = 0, Q_syn_Overl = 0, Q_syn_Overl_TDACFB = 0, Q_syn_OverlFB = 0, Q_old_out = 0, Q_old_outLB = 0, Q_old_Aq_12_8 = 0;
+        move16();
+        move16();
+        move16();
+        move16();
+        move16();
+        move16();
+        move16();
+        move16();
+
+        open_decoder_LPD_fx( st, total_brate, st->last_total_brate, bwidth, 0, EVS_MONO, 0, &Q_syn_Overl_TDAC, &Q_fer_samples, &Q_syn_Overl, &Q_syn_Overl_TDACFB, &Q_syn_OverlFB, &Q_old_out, &Q_old_outLB, &Q_old_Aq_12_8 );
+#else
         open_decoder_LPD_fx( st, total_brate, bwidth );
+#endif
     }
     ELSE
     {
@@ -323,7 +337,11 @@ void mode_switch_decoder_LPD_ivas_fx(
     assert( (Word16) ( st->sr_core / FRAMES_PER_SEC ) == extract_l( Mult_32_16( st->sr_core, INV_FRAME_PER_SEC_Q15 ) ) );
     IF( NE_16( fscale, st->fscale ) || switchWB || bSwitchFromAmrwbIO || EQ_16( st->last_codec_mode, MODE1 ) || st->force_lpd_reset )
     {
+#ifdef FIX_2509_HARMONIZE_OPEN_DECODER_LPD
+        open_decoder_LPD_fx( st, total_brate, last_total_brate, bwidth, MCT_flag, last_element_mode, 0, Q_syn_Overl_TDAC, Q_fer_samples, Q_syn_Overl, Q_syn_Overl_TDACFB, Q_syn_OverlFB, Q_old_out, Q_old_outLB, Q_old_Aq_12_8 );
+#else
         open_decoder_LPD_ivas_fx( st, total_brate, last_total_brate, bwidth, MCT_flag, last_element_mode, 0, Q_syn_Overl_TDAC, Q_fer_samples, Q_syn_Overl, Q_syn_Overl_TDACFB, Q_syn_OverlFB, Q_old_out, Q_old_outLB, Q_old_Aq_12_8 );
+#endif
     }
     ELSE
     {
diff --git a/lib_dec/init_dec_fx.c b/lib_dec/init_dec_fx.c
index bae2638e15c67d5ccb26102b92b4f527bc961233..999b763f6e3578c582bfa7bf8dd5f500a868de0c 100644
--- a/lib_dec/init_dec_fx.c
+++ b/lib_dec/init_dec_fx.c
@@ -878,12 +878,14 @@ ivas_error init_decoder_fx(
         st_fx->hTECDec = NULL;
     }
 
+#ifndef FIX_2509_HARMONIZE_OPEN_DECODER_LPD
     /* Init Decoder */
     IF( st_fx->element_mode == EVS_MONO )
     {
         open_decoder_LPD_fx( st_fx, st_fx->total_brate, st_fx->bwidth );
     }
     ELSE
+#endif
     {
         Word16 Q_syn_Overl_TDAC = 0, Q_fer_samples = 0, Q_syn_Overl = 0, Q_syn_Overl_TDACFB = 0, Q_syn_OverlFB = 0, Q_old_out = 0, Q_old_outLB = 0, Q_old_Aq_12_8 = 0;
         move16();
@@ -894,7 +896,11 @@ ivas_error init_decoder_fx(
         move16();
         move16();
         move16();
+#ifdef FIX_2509_HARMONIZE_OPEN_DECODER_LPD
+        open_decoder_LPD_fx( st_fx, st_fx->total_brate, st_fx->last_total_brate, st_fx->bwidth, 0, st_fx->element_mode, 1, &Q_syn_Overl_TDAC, &Q_fer_samples, &Q_syn_Overl, &Q_syn_Overl_TDACFB, &Q_syn_OverlFB, &Q_old_out, &Q_old_outLB, &Q_old_Aq_12_8 );
+#else
         open_decoder_LPD_ivas_fx( st_fx, st_fx->total_brate, st_fx->last_total_brate, st_fx->bwidth, 0, st_fx->element_mode, 1, &Q_syn_Overl_TDAC, &Q_fer_samples, &Q_syn_Overl, &Q_syn_Overl_TDACFB, &Q_syn_OverlFB, &Q_old_out, &Q_old_outLB, &Q_old_Aq_12_8 );
+#endif
     }
 
     /* PLC mode initialization */