diff --git a/lib_com/options.h b/lib_com/options.h
index 7fa610801bd2a2942126d5f7c449a42ed0a3fe3e..e2bfae0d35e41f7734e03e1a74eb27138dd36441 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -103,6 +103,7 @@
 #define FIX_2458_USAN_NULLPTR_WITH_ZERO_OFFSET          /* FhG: basop issue 2458: avoid indexing into null pointer */
 #define HARM_2456_APPLY_SCALE                           /* FhG basop issue 2456: Harmonize apply_scale_ind(), apply_scale_ivas_fx() */
 #define HARM_2454_TCX_RES_Q_SPEC                        /* FhG: harmonization of tcx_res_Q_spec_fx() and tcx_res_Q_spec_ivas_fx() */
+#define FIX_FLOAT_1535_ARI_RES_Q_CLEANUP                /* FhG: remove dead code from tcx_ari_res_Q_spec() */
 
 /* #################### End BE switches ################################## */
 
diff --git a/lib_enc/cod_tcx_fx.c b/lib_enc/cod_tcx_fx.c
index 71d22d2a8c85a1b1bfa90e000c0c5ef421651146..12c3dd6d13b7d6634fe2e876eb464ce4079d775a 100644
--- a/lib_enc/cod_tcx_fx.c
+++ b/lib_enc/cod_tcx_fx.c
@@ -3570,7 +3570,11 @@ void QuantizeTCXSpectrum_fx(
 
             prm_resq = sqQ + sub( sqTargetBits, resQTargetBits );
 
+#ifdef FIX_FLOAT_1535_ARI_RES_Q_CLEANUP
+            resQBits = tcx_ari_res_Q_spec_fx( x_orig_fx, x_orig_e, hm_cfg->indexBuffer, spectrum_fx, *spectrum_e, L_spec, *gain_tcx_fx, *gain_tcx_e, prm_resq, resQTargetBits, resQBits, st->hTcxCfg->sq_rounding, lf_deemph_fact_fx );
+#else
             resQBits = tcx_ari_res_Q_spec_ivas_fx( x_orig_fx, x_orig_e, hm_cfg->indexBuffer, spectrum_fx, *spectrum_e, L_spec, *gain_tcx_fx, *gain_tcx_e, prm_resq, resQTargetBits, resQBits, st->hTcxCfg->sq_rounding, lf_deemph_fact_fx );
+#endif
 
             /* Transmit zeros when there bits remain after RESQ */
             FOR( i = resQBits; i < resQTargetBits; ++i )
diff --git a/lib_enc/prot_fx_enc.h b/lib_enc/prot_fx_enc.h
index fc3c7928c2cbb4bf573d19419ebef5ae495af60a..698f1d14054be4f476d3232cee364fa8203ba8ce 100644
--- a/lib_enc/prot_fx_enc.h
+++ b/lib_enc/prot_fx_enc.h
@@ -1313,6 +1313,7 @@ Word16 tcx_ari_res_Q_spec_fx(
     const Word16 x_fac[]   /* i  : spectrum post-quantization factors  Q14 */
 );
 
+#ifndef FIX_FLOAT_1535_ARI_RES_Q_CLEANUP
 Word16 tcx_ari_res_Q_spec_ivas_fx(
     const Word32 x_orig[], /* i  : original spectrum                   Q31-e */
     Word16 x_orig_e,       /* i  : original spectrum exponent          Q0 */
@@ -1328,7 +1329,7 @@ Word16 tcx_ari_res_Q_spec_ivas_fx(
     Word16 deadzone,       /* i  : quantizer deadzone                  Q15 */
     const Word16 x_fac[]   /* i  : spectrum post-quantization factors  Q14 */
 );
-
+#endif
 Word16 tcx_res_Q_gain_fx(
     Word16 sqGain,
     Word16 sqGain_e,
diff --git a/lib_enc/tcx_utils_enc_fx.c b/lib_enc/tcx_utils_enc_fx.c
index 1ada17a8f538da95f1d1486180467732134ddce6..882c71bc20b6eff362c53d88e7a13c2e422abe65 100644
--- a/lib_enc/tcx_utils_enc_fx.c
+++ b/lib_enc/tcx_utils_enc_fx.c
@@ -2996,6 +2996,10 @@ Word16 tcx_ari_res_Q_spec_fx(
     num_zeros = 0;
     move16();
 
+#ifdef FIX_FLOAT_1535_ARI_RES_Q_CLEANUP
+    assert( x_fac != NULL );
+#endif
+
     s = sub( add( gain_e, x_Q_e ), x_orig_e );
     FOR( i = 0; i < L_frame; i++ )
     {
@@ -3097,7 +3101,7 @@ Word16 tcx_ari_res_Q_spec_fx(
     return bits;
 }
 
-
+#ifndef FIX_FLOAT_1535_ARI_RES_Q_CLEANUP
 Word16 tcx_ari_res_Q_spec_ivas_fx(
     const Word32 x_orig[], /* i  : original spectrum                   Q31-e */
     Word16 x_orig_e,       /* i  : original spectrum exponent          Q0 */
@@ -3328,7 +3332,7 @@ Word16 tcx_ari_res_Q_spec_ivas_fx(
 
     return bits;
 }
-
+#endif
 
 #define kMaxEstimatorOvershoot  5
 #define kMaxEstimatorUndershoot 0