diff --git a/libavformat/rtpdec_h264.c b/libavformat/rtpdec_h264.c
index aa75062a61..e237a03d76 100644
--- a/libavformat/rtpdec_h264.c
+++ b/libavformat/rtpdec_h264.c
@@ -66,7 +66,7 @@ static const uint8_t start_sequence[] = { 0, 0, 0, 1 };
 
 static void parse_profile_level_id(AVFormatContext *s,
                                    PayloadContext *h264_data,
-                                   char *value)
+                                   const char *value)
 {
     char buffer[3];
     // 6 characters=3 bytes, in hex.
diff --git a/libavformat/rtpdec_latm.c b/libavformat/rtpdec_latm.c
index 8527bff6f8..bf255f83c0 100644
--- a/libavformat/rtpdec_latm.c
+++ b/libavformat/rtpdec_latm.c
@@ -96,7 +96,7 @@ static int latm_parse_packet(AVFormatContext *ctx, PayloadContext *data,
     return data->pos < data->len;
 }
 
-static int parse_fmtp_config(AVStream *st, char *value)
+static int parse_fmtp_config(AVStream *st, const char *value)
 {
     int len = ff_hex_to_data(NULL, value), i, ret = 0;
     GetBitContext gb;
diff --git a/libavformat/rtpdec_mpeg4.c b/libavformat/rtpdec_mpeg4.c
index 27184d9faa..531d076aa5 100644
--- a/libavformat/rtpdec_mpeg4.c
+++ b/libavformat/rtpdec_mpeg4.c
@@ -98,7 +98,7 @@ static void free_context(PayloadContext *data)
     av_freep(&data);
 }
 
-static int parse_fmtp_config(AVCodecContext *codec, char *value)
+static int parse_fmtp_config(AVCodecContext *codec, const char *value)
 {
     /* decode the hexa encoded parameter */
     int len = ff_hex_to_data(NULL, value);