diff --git a/lib_com/options.h b/lib_com/options.h
index 909061536ed6f1450d9c53ff5da97fba8e95543f..328d1aa08128e4fedf1b45d2424aa0a3c6a7b9e1 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -193,6 +193,7 @@
 #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.c b/lib_rend/ivas_rotation.c
index a829db866d320e3962212bd72b190f6e5b763e1d..4fb8217e5c434bc9d684830a3b5db4e5b531c2e8 100644
--- a/lib_rend/ivas_rotation.c
+++ b/lib_rend/ivas_rotation.c
@@ -508,7 +508,12 @@ void rotateFrame_shd_cldfb(
     float realRot[2 * HEADROT_ORDER + 1], imagRot[2 * HEADROT_ORDER + 1];
     float SHrotmat[HEADROT_SHMAT_DIM][HEADROT_SHMAT_DIM];
 
+#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.c b/lib_rend/lib_rend.c
index 3fc2347752a268c6cf40815347e7d32e6bc6b9b4..07c3d6086fc4a715862be113bd81880592847133 100644
--- a/lib_rend/lib_rend.c
+++ b/lib_rend/lib_rend.c
@@ -2565,7 +2565,11 @@ static ivas_error updateSbaPanGains(
                     if ( 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;
@@ -4274,7 +4278,11 @@ ivas_error IVAS_REND_InitConfig(
  *
  *-------------------------------------------------------------------*/
 
+#ifdef FIX_1113_EXTREND_ISAR
+ivas_error IVAS_REND_GetRenderConfig(
+#else
 int16_t IVAS_REND_GetRenderConfig(
+#endif
     IVAS_REND_HANDLE hIvasRend,            /* i/o: IVAS renderer handle        */
     const IVAS_RENDER_CONFIG_HANDLE hRCout /* o  : Render configuration handle */
 )
@@ -4338,7 +4346,11 @@ int16_t IVAS_REND_GetRenderConfig(
  *
  *-------------------------------------------------------------------*/
 
+#ifdef FIX_1113_EXTREND_ISAR
+ivas_error IVAS_REND_FeedRenderConfig(
+#else
 int16_t 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.h b/lib_rend/lib_rend.h
index 463e1a88220f98460ebcbdb8158a957c1e575cd6..4ed038df97d6858991f8358569e6d384982e4a09 100644
--- a/lib_rend/lib_rend.h
+++ b/lib_rend/lib_rend.h
@@ -246,12 +246,21 @@ ivas_error IVAS_REND_InitConfig(
     const IVAS_AUDIO_CONFIG outAudioConfig          /* i  : output audioConfig                                  */
 );
 
+#ifdef FIX_1113_EXTREND_ISAR
+ivas_error IVAS_REND_GetRenderConfig(
+#else
 int16_t 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
 int16_t IVAS_REND_FeedRenderConfig(
+#endif
     IVAS_REND_HANDLE hIvasRend,                     /* i/o: IVAS renderer handle                                */
     const IVAS_RENDER_CONFIG_DATA renderConfig      /* i  : Render configuration struct                         */
 );