diff --git a/README.md b/README.md
index 4905417..65395e6 100644
--- a/README.md
+++ b/README.md
@@ -19,6 +19,7 @@ cd minimap2 && make
 ./minimap2 -ax splice ref.fa rna-reads.fa > aln.sam       # spliced long reads (strand unknown)
 ./minimap2 -ax splice -uf -k14 ref.fa reads.fa > aln.sam  # noisy Nanopore Direct RNA-seq
 ./minimap2 -ax splice:hq -uf ref.fa query.fa > aln.sam    # Final PacBio Iso-seq or traditional cDNA
+./minimap2 -ax splice --junc-bed anno.bed12 ref.fa query.fa > aln.sam  # prioritize on annotated junctions
 ./minimap2 -cx asm5 asm1.fa asm2.fa > aln.paf             # intra-species asm-to-asm alignment
 ./minimap2 -x ava-pb reads.fa reads.fa > overlaps.paf     # PacBio read overlap
 ./minimap2 -x ava-ont reads.fa reads.fa > overlaps.paf    # Nanopore read overlap
@@ -185,6 +186,19 @@ This is because SIRV does not honor the evolutionarily conservative splicing
 signal. If you are studying SIRV, you may apply `--splice-flank=no` to let
 minimap2 only model GT..AG, ignoring the additional base.
 
+Since v2.17, minimap2 can optionally take annotated genes as input and
+prioritize on annotated splice junctions. To use this feature, you can 
+```sh
+paftools.js gff2bed anno.gff > anno.bed
+minimap2 -ax splice --junc-bed anno.bed ref.fa query.fa > aln.sam
+```
+Here, `anno.gff` is the gene annotation in the GTF or GFF3 format (`gff2bed`
+automatically tests the format). The output of `gff2bed` is in the 12-column
+BED format, or the BED12 format. With the `--junc-bed` option, minimap2 adds a
+bonus score (tuned by `--junc-bonus`) if an aligned junction matches a junction
+in the annotation. Option `--junc-bed` also takes 5-column BED, including the
+strand field. In this case, each line indicates an oriented junction.
+
 #### <a name="long-overlap"></a>Find overlaps between long reads
 
 ```sh
diff --git a/minimap2.1 b/minimap2.1
index aeb1492..9e55543 100644
--- a/minimap2.1
+++ b/minimap2.1
@@ -391,7 +391,7 @@ BED12 file can be converted from GTF/GFF3 with `paftools.js gff2bed anno.gtf'
 .BR --junc-bonus \ INT
 Score bonus for a splice donor or acceptor found in annotation (effective with
 .BR --junc-bed )
-[0].
+[9].
 .TP
 .BI --end-seed-pen \ INT
 Drop a terminal anchor if