diff --git a/lib_com/options.h b/lib_com/options.h
index e1eaa1221cbe14dc4b53da795604ae4b0351fe8a..e28f39446973f98872bb0121828fb97ba5953e5d 100755
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -153,6 +153,7 @@
 
 #define FIX_963_USAN_ERROR                              /* Eri: Issue 963: USAN error in Stereo CNG, division by zero */
 #define FIX_971_LOG2_IDX_GAIN_0                         /* VA: prevent -Inf due to log2(ratio==0) */
+#define FIX_983_DISC_ISM_DIGEST_NUM_OBJS                /* FhG: issue #983: the discrete ISM digest function uses the wrong number of objects */
 
 /* #################### End BE switches ################################## */
 
diff --git a/lib_dec/ivas_ism_param_dec.c b/lib_dec/ivas_ism_param_dec.c
index da12741551cfbaf5e0a9f1547b6e71b1a49bc627..b458e2c7135d5260fc4dd245fb3824d393158751 100644
--- a/lib_dec/ivas_ism_param_dec.c
+++ b/lib_dec/ivas_ism_param_dec.c
@@ -996,7 +996,11 @@ void ivas_ism_dec_digest_tc(
          st_ivas->renderer_type == RENDERER_OSBA_STEREO ||
          ( st_ivas->renderer_type == RENDERER_BINAURAL_MIXER_CONV_ROOM && st_ivas->hDecoderConfig->Opt_Headrotation == 0 ) )
     {
+#ifdef FIX_983_DISC_ISM_DIGEST_NUM_OBJS
+        int16_t i;
+#else
         int16_t i, num_objects;
+#endif
         int16_t azimuth, elevation;
 
         /* we have a full frame interpolator, adapt it */
@@ -1029,8 +1033,13 @@ void ivas_ism_dec_digest_tc(
         }
 
         /* also get the gains here */
+#ifdef FIX_983_DISC_ISM_DIGEST_NUM_OBJS
+        for ( i = 0; i < st_ivas->nchan_ism; i++ )
+#else
         num_objects = st_ivas->nchan_transport;
+
         for ( i = 0; i < num_objects; i++ )
+#endif
         {
             mvr2r( st_ivas->hIsmRendererData->gains[i], st_ivas->hIsmRendererData->prev_gains[i], MAX_OUTPUT_CHANNELS );