diff --git a/libavformat/applehttpproto.c b/libavformat/applehttpproto.c
index c7e12a9fb81f6d24333060fe95383daab24bef4e..64becf4634d63b28698297124634a75d9fee7792 100644
--- a/libavformat/applehttpproto.c
+++ b/libavformat/applehttpproto.c
@@ -181,7 +181,7 @@ static int applehttp_open(URLContext *h, const char *uri, int flags)
     const char *nested_url;
 
     if (flags & (URL_WRONLY | URL_RDWR))
-        return AVERROR_NOTSUPP;
+        return AVERROR(ENOSYS);
 
     s = av_mallocz(sizeof(AppleHTTPContext));
     if (!s)
diff --git a/libavformat/assdec.c b/libavformat/assdec.c
index a50150513c6b244c71efb92b2d43e8055e1218bb..b270200af2cba769f982029ca5ab688b96a78b6b 100644
--- a/libavformat/assdec.c
+++ b/libavformat/assdec.c
@@ -168,7 +168,7 @@ static int read_seek2(AVFormatContext *s, int stream_index,
     ASSContext *ass = s->priv_data;
 
     if (flags & AVSEEK_FLAG_BYTE) {
-        return AVERROR_NOTSUPP;
+        return AVERROR(ENOSYS);
     } else if (flags & AVSEEK_FLAG_FRAME) {
         if (ts < 0 || ts >= ass->event_count)
             return AVERROR(ERANGE);
diff --git a/libavformat/jvdec.c b/libavformat/jvdec.c
index c180e5db4c1116bc114a77c9a4fb9d2631ce132a..d4008f7148a5887efe2aa944c7037e22990cc1c1 100644
--- a/libavformat/jvdec.c
+++ b/libavformat/jvdec.c
@@ -192,7 +192,7 @@ static int read_seek(AVFormatContext *s, int stream_index,
     int i;
 
     if (flags & (AVSEEK_FLAG_BYTE|AVSEEK_FLAG_FRAME))
-        return AVERROR_NOTSUPP;
+        return AVERROR(ENOSYS);
 
     switch(stream_index) {
     case 0:
diff --git a/libavformat/rtpdec_qt.c b/libavformat/rtpdec_qt.c
index 24977ed753518099bca7b8ca1f29ef3dd3a3f8c8..a295ba7381c5fc8c7ec55be0e31db0860ff1b5c2 100644
--- a/libavformat/rtpdec_qt.c
+++ b/libavformat/rtpdec_qt.c
@@ -98,7 +98,7 @@ static int qt_rtp_parse_packet(AVFormatContext *s, PayloadContext *qt,
         if (!is_start || !is_finish) {
             av_log_missing_feature(s, "RTP-X-QT with payload description "
                                       "split over several packets", 1);
-            return AVERROR_NOTSUPP;
+            return AVERROR(ENOSYS);
         }
         skip_bits(&gb, 12); // reserved
         data_len = get_bits(&gb, 16);
@@ -161,7 +161,7 @@ static int qt_rtp_parse_packet(AVFormatContext *s, PayloadContext *qt,
 
     if (has_packet_info) {
         av_log_missing_feature(s, "RTP-X-QT with packet specific info", 1);
-        return AVERROR_NOTSUPP;
+        return AVERROR(ENOSYS);
     }
 
     alen = len - avio_tell(&pb);
@@ -224,7 +224,7 @@ static int qt_rtp_parse_packet(AVFormatContext *s, PayloadContext *qt,
 
     default:  /* unimplemented */
         av_log_missing_feature(NULL, "RTP-X-QT with packing scheme 2", 1);
-        return AVERROR_NOTSUPP;
+        return AVERROR(ENOSYS);
     }
 }
 
diff --git a/libavformat/wtv.c b/libavformat/wtv.c
index 963a6bc7532f89d30aada7914d97be91785a95f0..8260fe19b22cbe1651669943a8cc0125052e1de8 100644
--- a/libavformat/wtv.c
+++ b/libavformat/wtv.c
@@ -1061,7 +1061,7 @@ static int read_seek(AVFormatContext *s, int stream_index,
     int i;
 
     if ((flags & AVSEEK_FLAG_FRAME) || (flags & AVSEEK_FLAG_BYTE))
-        return AVERROR_NOTSUPP;
+        return AVERROR(ENOSYS);
 
     /* timestamp adjustment is required because wtv->pts values are absolute,
      * whereas AVIndexEntry->timestamp values are relative to epoch. */