diff --git a/include/FLAC/stream_decoder.h b/include/FLAC/stream_decoder.h
index 50ebfa80..57215c5e 100644
--- a/include/FLAC/stream_decoder.h
+++ b/include/FLAC/stream_decoder.h
@@ -1550,16 +1550,6 @@ FLAC_API FLAC__bool FLAC__stream_decoder_skip_single_frame(FLAC__StreamDecoder *
  */
 FLAC_API FLAC__bool FLAC__stream_decoder_seek_absolute(FLAC__StreamDecoder *decoder, FLAC__uint64 sample);
 
-/** Return client_data from decoder.
- *  The data pointed to by the pointer should not be modified.
- *
- * \param  decoder  A decoder instance.
- * \retval const void *
- *    The callee's client data set through FLAC__stream_decoder_init_*().
- *    Do not modify the contents.
- */
-FLAC_API const void *FLAC__get_decoder_client_data(FLAC__StreamDecoder *decoder);
-
 /* \} */
 
 #ifdef __cplusplus
diff --git a/src/libFLAC/include/protected/stream_decoder.h b/src/libFLAC/include/protected/stream_decoder.h
index 2f3996b3..99092751 100644
--- a/src/libFLAC/include/protected/stream_decoder.h
+++ b/src/libFLAC/include/protected/stream_decoder.h
@@ -57,4 +57,9 @@ typedef struct FLAC__StreamDecoderProtected {
  */
 uint32_t FLAC__stream_decoder_get_input_bytes_unconsumed(const FLAC__StreamDecoder *decoder);
 
+/*
+ * Return client_data from decoder. The data pointed to by the pointer should not be modified.
+ */
+FLAC_API const void *FLAC__get_decoder_client_data(FLAC__StreamDecoder *decoder);
+
 #endif