diff --git a/lib_com/options.h b/lib_com/options.h
index 03fa967de0a6a3b9a1c27112052470503f843723..fdf73590af6074644fa8e279a5379377dfbe9e0e 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -136,6 +136,7 @@
 #define ADJUST_MCT_CHANNELS_MAX                         /* FhG: set correct max mct channels constant*/
 #define FIX_1053_REVERB_RECONFIGURATION
 #define TMP_FIX_1119_SPLIT_RENDERING_VOIP               /* FhG: Add error check for unsupported config: split rendering with VoIP mode */
+#define FIX_1113_EXTREND_ISAR                           /* FhG: issue 1113: fix external renderer asserts for FOA/HOA2 and CLDFB config */
 
 /* #################### End BASOP porting switches ############################ */
 
diff --git a/lib_rend/ivas_rotation_fx.c b/lib_rend/ivas_rotation_fx.c
index d8e18f8a6863a39508543a78ab52630e08f74508..0524155c89f962cb5a76017ecbfc25369740d058 100644
--- a/lib_rend/ivas_rotation_fx.c
+++ b/lib_rend/ivas_rotation_fx.c
@@ -1022,7 +1022,13 @@ void rotateFrame_shd_cldfb(
     move16();
     move16();
     move16();
+
+#ifdef FIX_1113_EXTREND_ISAR
+    assert( ( nInChannels == HOA3_CHANNELS || nInChannels == HOA2_CHANNELS || nInChannels == FOA_CHANNELS ) &&
+            "Number of channels must correspond to an ambisonics order!" );
+#else
     assert( nInChannels == HEADROT_SHMAT_DIM && "Number of channels must be 16!" );
+#endif
 
     /* initialize rotation matrices with zeros */
     FOR( i = 0; i < HEADROT_SHMAT_DIM; i++ )
diff --git a/lib_rend/lib_rend.h b/lib_rend/lib_rend.h
index 7289ced5cd4cf772e97bb030868c14059418d0fe..1f46ca932d417270d2b8a2c80c03061291959156 100644
--- a/lib_rend/lib_rend.h
+++ b/lib_rend/lib_rend.h
@@ -255,12 +255,20 @@ ivas_error IVAS_REND_InitConfig(
     const IVAS_AUDIO_CONFIG outAudioConfig          /* i  : output audioConfig                                  */
 );
 
+#ifdef FIX_1113_EXTREND_ISAR
+ivas_error IVAS_REND_GetRenderConfig(
+#else
 Word16 IVAS_REND_GetRenderConfig(
+#endif
     IVAS_REND_HANDLE hIvasRend,                     /* i/o: IVAS renderer handle                                */
     const IVAS_RENDER_CONFIG_HANDLE hRCout          /* o  : Render configuration handle                         */
 );
 
+#ifdef FIX_1113_EXTREND_ISAR
+ivas_error IVAS_REND_FeedRenderConfig(
+#else
 Word16 IVAS_REND_FeedRenderConfig(
+#endif
     IVAS_REND_HANDLE hIvasRend,                     /* i/o: IVAS renderer handle                                */
     const IVAS_RENDER_CONFIG_DATA renderConfig      /* i  : Render configuration struct                         */
 );
diff --git a/lib_rend/lib_rend_fx.c b/lib_rend/lib_rend_fx.c
index fc72052b7611fcfda424dff0373501aa087f2a54..dc53538bb28be7ab47b8fba7a37b7d952a84566f 100644
--- a/lib_rend/lib_rend_fx.c
+++ b/lib_rend/lib_rend_fx.c
@@ -3107,7 +3107,11 @@ static ivas_error updateSbaPanGains(
                     IF( EQ_32( hRendCfg->split_rend_config.rendererSelection, ISAR_SPLIT_REND_RENDERER_SELECTION_FASTCONV ) )
 #endif
                     {
+#ifdef FIX_1113_EXTREND_ISAR
+                        assert( *rendCtx.pOutSampleRate == 48000 && "split binaural fast conv mode is currently supported with 48k sampling rate only" );
+#else
                         assert( inConfig == IVAS_AUDIO_CONFIG_HOA3 && ( *rendCtx.pOutSampleRate == 48000 ) && "split binaural fast conv mode is currently supported with HOA3 input and 48k sampling rate only" );
+#endif
                         IF( ( error = ivas_rend_openCldfbRend( &inputSba->cldfbRendWrapper, inConfig, outConfig, &rendCtx.pSplitRendWrapper->multiBinPoseData, *rendCtx.pOutSampleRate ) ) != IVAS_ERR_OK )
                         {
                             return error;
@@ -4982,7 +4986,11 @@ ivas_error IVAS_REND_InitConfig(
  *
  *-------------------------------------------------------------------*/
 
+#ifdef FIX_1113_EXTREND_ISAR
+ivas_error IVAS_REND_GetRenderConfig(
+#else
 Word16 IVAS_REND_GetRenderConfig(
+#endif
     IVAS_REND_HANDLE hIvasRend,            /* i/o: IVAS renderer handle        */
     const IVAS_RENDER_CONFIG_HANDLE hRCout /* o  : Render configuration handle */
 )
@@ -5039,7 +5047,11 @@ Word16 IVAS_REND_GetRenderConfig(
  *
  *-------------------------------------------------------------------*/
 
+#ifdef FIX_1113_EXTREND_ISAR
+ivas_error IVAS_REND_FeedRenderConfig(
+#else
 Word16 IVAS_REND_FeedRenderConfig(
+#endif
     IVAS_REND_HANDLE hIvasRend,                /* i/o: IVAS renderer handle        */
     const IVAS_RENDER_CONFIG_DATA renderConfig /* i  : Render configuration struct */
 )