diff --git a/include/opus_multistream.h b/include/opus_multistream.h
index 658067f..ae59979 100644
--- a/include/opus_multistream.h
+++ b/include/opus_multistream.h
@@ -205,6 +205,12 @@
       int coupled_streams
 );
 
+OPUS_EXPORT OPUS_WARN_UNUSED_RESULT opus_int32 opus_multistream_surround_encoder_get_size(
+      int channels,
+      int mapping_family
+);
+
+
 /** Allocates and initializes a multistream encoder state.
   * Call opus_multistream_encoder_destroy() to release
   * this object when finished.
@@ -258,6 +264,17 @@
       int *error
 ) OPUS_ARG_NONNULL(5);
 
+OPUS_EXPORT OPUS_WARN_UNUSED_RESULT OpusMSEncoder *opus_multistream_surround_encoder_create(
+      opus_int32 Fs,
+      int channels,
+      int mapping_family,
+      int *streams,
+      int *coupled_streams,
+      unsigned char *mapping,
+      int application,
+      int *error
+) OPUS_ARG_NONNULL(5);
+
 /** Initialize a previously allocated multistream encoder state.
   * The memory pointed to by \a st must be at least the size returned by
   * opus_multistream_encoder_get_size().
@@ -316,6 +333,17 @@
       int application
 ) OPUS_ARG_NONNULL(1) OPUS_ARG_NONNULL(6);
 
+OPUS_EXPORT int opus_multistream_surround_encoder_init(
+      OpusMSEncoder *st,
+      opus_int32 Fs,
+      int channels,
+      int mapping_family,
+      int *streams,
+      int *coupled_streams,
+      unsigned char *mapping,
+      int application
+) OPUS_ARG_NONNULL(1) OPUS_ARG_NONNULL(6);
+
 /** Encodes a multistream Opus frame.
   * @param st <tt>OpusMSEncoder*</tt>: Multistream encoder state.
   * @param[in] pcm <tt>const opus_int16*</tt>: The input signal as interleaved