diff --git a/lib_com/options.h b/lib_com/options.h
index e422a9e12ff5f48b17d1b6fe026f03ca4459c082..c0b8c7f094af2c4077c9dbf8248792aac7405ceb 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -193,6 +193,7 @@
 #define FIX_NCHAN_BUFFERS                               /* VA: issue 1322: Correct the number of float buffers (channels) at the decoder */
 #define FIX_RENDERER_STACK                              /* VA: issue 1322: reduction of renderers' buffers size */
 #define FIX_1370_EXTERNAL_ORIENTATION_CHECK             /* Nokia: add sanity check for Euler angles for external orientations */
+#define NONBE_FIX_1197_OMASA_META_BUFFER                /* Nokia: OMASA ISM_MASA_MODE_PARAM_ONE_OBJ history zero in rateswitching - port 251 */
 
 // object-editing feature porting
 #define FIX_HRTF_LOAD_API                               // solves API conflicts between HRTF and object-editing features
diff --git a/lib_dec/ivas_omasa_dec.c b/lib_dec/ivas_omasa_dec.c
index 917af3b9e6340ddcd76dabb009972b44636eb9e3..44d4b70ca0e45b3a5d23f2b8f11aa1cf86c9bd64 100644
--- a/lib_dec/ivas_omasa_dec.c
+++ b/lib_dec/ivas_omasa_dec.c
@@ -334,6 +334,24 @@ ivas_error ivas_omasa_dec_config(
             ivas_omasa_separate_object_renderer_close( st_ivas );
         }
 
+#ifdef NONBE_FIX_1197_OMASA_META_BUFFER
+        if ( st_ivas->ism_mode == ISM_MASA_MODE_PARAM_ONE_OBJ && st_ivas->hMasaIsmData != NULL ) /* this structure is in use only in ISM_MASA_MODE_PARAM_ONE_OBJ */
+        {
+            MASA_ISM_DATA_HANDLE hMasaIsmData = st_ivas->hMasaIsmData;
+            for ( int16_t obj_idx = 0; obj_idx < MAX_NUM_OBJECTS; obj_idx++ )
+            {
+                set_s( hMasaIsmData->azimuth_ism[obj_idx], 0, MAX_PARAM_SPATIAL_SUBFRAMES + DELAY_MASA_PARAM_DEC_SFR );
+                set_s( hMasaIsmData->elevation_ism[obj_idx], 0, MAX_PARAM_SPATIAL_SUBFRAMES + DELAY_MASA_PARAM_DEC_SFR );
+                for ( int16_t sf = 0; sf < MAX_PARAM_SPATIAL_SUBFRAMES + DELAY_MASA_PARAM_DEC_SFR; sf++ )
+                {
+                    set_zero( hMasaIsmData->energy_ratio_ism[obj_idx][sf], CLDFB_NO_CHANNELS_MAX );
+                }
+            }
+            set_s( hMasaIsmData->azimuth_separated_ism, 0, MAX_PARAM_SPATIAL_SUBFRAMES + DELAY_MASA_PARAM_DEC_SFR );
+            set_s( hMasaIsmData->elevation_separated_ism, 0, MAX_PARAM_SPATIAL_SUBFRAMES + DELAY_MASA_PARAM_DEC_SFR );
+        }
+#endif
+
         if ( st_ivas->renderer_type == RENDERER_BINAURAL_PARAMETRIC )
         {
             if ( st_ivas->ism_mode == ISM_MASA_MODE_DISC )
diff --git a/lib_rend/ivas_dirac_dec_binaural_functions.c b/lib_rend/ivas_dirac_dec_binaural_functions.c
index 7193f78d27d361b684d645f77395233dd546d752..83a8f6bb4fefd1d992dc4e4d2d705325501ab2f9 100644
--- a/lib_rend/ivas_dirac_dec_binaural_functions.c
+++ b/lib_rend/ivas_dirac_dec_binaural_functions.c
@@ -3130,16 +3130,25 @@ void ivas_omasa_preProcessStereoTransportsForEditedObjects(
                 ratioAccNew += ratio;
             }
 
+            /* Todo: Remove this comment with port 408 which would bring this back.
+             *       No sense to break the code with port 251. */
             /* Limit target energies to non-negative values */
             for ( ch = 0; ch < 2; ch++ )
             {
                 totalTargetEneCh[ch] = max( totalTargetEneCh[ch], 0.0f );
             }
 
-            /* Diffuse ratio accumulation based on gaining */
+#ifdef NONBE_FIX_1197_OMASA_META_BUFFER
+            /* due to rounding, the sum may exceed 1.0f ever so slightly, so clip it */
+            ratioAccOrig = min( ratioAccOrig, 1.0f );
+#endif
             if ( masaGainEdited )
             {
+#ifdef NONBE_FIX_1197_OMASA_META_BUFFER
+                ratioAccNew += gainMasaPow2 * ( 1.0f - ratioAccOrig );
+#else
                 ratioAccNew += gainMasaPow2 * ( 1 - ratioAccOrig );
+#endif
             }
             else
             {