diff --git a/lib_com/options.h b/lib_com/options.h
old mode 100644
new mode 100755
index da412cd9b9a161703e5dac3a225b997a9576f60d..1f39c1eaed1d802d3a505b0a95bfd6ea53e3d825
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -181,10 +181,13 @@
 #define MASA_PREREND                                    /* Nokia: Contribution 42: Support for IVAS_rend to merge MASA + other format to MASA */
 #define FIX_383_CLEAN_UP                                /* Dlb : Clean up of unused functions */
 #define ISM_25k6_HZ_CORE                                /* VA: issue 540: 1ISM 48 kbps - change ACELP/TCX 16 kHz core to TCX only 25.6 kHz core */
+
 #define FIX_528_ISM_MD_FILE_TOO_SHORT                   /* VA: issue 528: ISM Metadata file too short  */
 
 #define FIX_532_ISM_MD_INACTIVE                         /* VA: issue 532: improve MD coding in ISM inactive frames */
 
+#define FIX_547_NAN_IGF_DEC                             /* FhG: issue 547: fix possible nan in IGF decoder */
+
 /* ################## End DEVELOPMENT switches ######################### */
 /* clang-format on */
 
diff --git a/lib_dec/igf_dec.c b/lib_dec/igf_dec.c
old mode 100644
new mode 100755
index a3eefd226ebe39c0baf910d806afaecef48c188d..b9049241b9dadea62d3cde01358fcee132459965
--- a/lib_dec/igf_dec.c
+++ b/lib_dec/igf_dec.c
@@ -165,6 +165,10 @@ static void IGF_replaceTCXNoise_2_new(
         }
     }
 
+#ifdef FIX_547_NAN_IGF_DEC
+    rE = max( rE, 1.f );
+#endif
+
     if ( n_noise_bands_tile )
     {
         noise_band_ratio = (float) n_noise_bands_tile / n_noise_bands;