diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index 93ba4d087c..ba1873137d 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -4277,7 +4277,7 @@ typedef struct AVCodecParser {
     struct AVCodecParser *next;
 } AVCodecParser;
 
-AVCodecParser *av_parser_next(AVCodecParser *c);
+AVCodecParser *av_parser_next(const AVCodecParser *c);
 
 void av_register_codec_parser(AVCodecParser *parser);
 AVCodecParserContext *av_parser_init(int codec_id);
@@ -5001,7 +5001,7 @@ void av_bitstream_filter_close(AVBitStreamFilterContext *bsf);
  * This function can be used to iterate over all registered bitstream
  * filters.
  */
-AVBitStreamFilter *av_bitstream_filter_next(AVBitStreamFilter *f);
+AVBitStreamFilter *av_bitstream_filter_next(const AVBitStreamFilter *f);
 
 /* memory */
 
@@ -5069,7 +5069,7 @@ void av_register_hwaccel(AVHWAccel *hwaccel);
  * if hwaccel is non-NULL, returns the next registered hardware accelerator
  * after hwaccel, or NULL if hwaccel is the last one.
  */
-AVHWAccel *av_hwaccel_next(AVHWAccel *hwaccel);
+AVHWAccel *av_hwaccel_next(const AVHWAccel *hwaccel);
 
 
 /**
diff --git a/libavcodec/bitstream_filter.c b/libavcodec/bitstream_filter.c
index 3ee582fb28..751b90d1d5 100644
--- a/libavcodec/bitstream_filter.c
+++ b/libavcodec/bitstream_filter.c
@@ -26,7 +26,7 @@
 
 static AVBitStreamFilter *first_bitstream_filter = NULL;
 
-AVBitStreamFilter *av_bitstream_filter_next(AVBitStreamFilter *f)
+AVBitStreamFilter *av_bitstream_filter_next(const AVBitStreamFilter *f)
 {
     if (f)
         return f->next;
diff --git a/libavcodec/parser.c b/libavcodec/parser.c
index 3169e2501f..71449ca3ab 100644
--- a/libavcodec/parser.c
+++ b/libavcodec/parser.c
@@ -30,7 +30,7 @@
 
 static AVCodecParser *av_first_parser = NULL;
 
-AVCodecParser *av_parser_next(AVCodecParser *p)
+AVCodecParser *av_parser_next(const AVCodecParser *p)
 {
     if (p)
         return p->next;
diff --git a/libavcodec/utils.c b/libavcodec/utils.c
index 24f059e699..6071380c40 100644
--- a/libavcodec/utils.c
+++ b/libavcodec/utils.c
@@ -3401,7 +3401,7 @@ void av_register_hwaccel(AVHWAccel *hwaccel)
     last_hwaccel = &hwaccel->next;
 }
 
-AVHWAccel *av_hwaccel_next(AVHWAccel *hwaccel)
+AVHWAccel *av_hwaccel_next(const AVHWAccel *hwaccel)
 {
     return hwaccel ? hwaccel->next : first_hwaccel;
 }