diff --git a/configure b/configure
index 4d1f74efb3..a756eead9a 100755
--- a/configure
+++ b/configure
@@ -1570,8 +1570,8 @@ _amr_wb=auto
 _libavdecoders=`grep 'register_avcodec(&[a-z0-9_]*_decoder)' libavcodec/allcodecs.c  | sed 's/.*&\(.*\)).*/\1/'`
 _libavencoders=`grep 'register_avcodec(&[a-z0-9_]*_encoder)' libavcodec/allcodecs.c  | sed 's/.*&\(.*\)).*/\1/'`
 _libavparsers=`grep 'av_register_codec_parser(&[a-z]' libavcodec/allcodecs.c  | sed 's/.*&\(.*\)).*/\1/'`
-_libavdemuxers=`grep 'av_register_input_format(&[a-z]' libavformat/allformats.c  | sed 's/.*&\(.*\)).*/\1/'`
-_libavmuxers=`grep 'av_register_output_format(&[a-z]' libavformat/allformats.c  | sed 's/.*&\(.*\)).*/\1/'`
+_libavdemuxers=`sed -n 's/^[^#]*DEMUX.*, *\(.*\)).*/\1_demuxer/p' libavformat/allformats.c`
+_libavmuxers=`sed -n 's/^[^#]*_MUX.*, *\(.*\)).*/\1_muxer/p' libavformat/allformats.c`
 _libavcodec_so=auto
 _libavformat=auto
 _libavformat_so=auto