diff --git a/lib_rend/lib_rend_fx.c b/lib_rend/lib_rend_fx.c
index 2b0f1bdea6b296eacd1b763e0b1f85f3fd02653a..97b83b7b6b6f6bbac45494a757e79926142dc6f5 100644
--- a/lib_rend/lib_rend_fx.c
+++ b/lib_rend/lib_rend_fx.c
@@ -9905,7 +9905,12 @@ static ivas_error initMasaExtRenderer(
         return error;
     }
 
-    IF( NE_32( ( error = getAudioConfigNumChannels( outConfig, &hMasaExtRend->nchan_output ) ), IVAS_ERR_OK ) )
+    IF( EQ_32( outConfig, IVAS_AUDIO_CONFIG_LS_CUSTOM ) )
+    {
+        hMasaExtRend->nchan_output = add( inputMasa->base.ctx.pCustomLsOut->num_spk, inputMasa->base.ctx.pCustomLsOut->num_lfe );
+        move16();
+    }
+    ELSE IF( NE_32( ( error = getAudioConfigNumChannels( outConfig, &hMasaExtRend->nchan_output ) ), IVAS_ERR_OK ) )
     {
         return error;
     }