diff --git a/src/bcftools/bcftools_sort/help.txt b/src/bcftools/bcftools_sort/help.txt
index 7c6adc95..3b5fa80b 100644
--- a/src/bcftools/bcftools_sort/help.txt
+++ b/src/bcftools/bcftools_sort/help.txt
@@ -6,8 +6,9 @@ About:   Sort VCF/BCF file.
 Usage:   bcftools sort [OPTIONS] <FILE.vcf>
 
 Options:
-    -m, --max-mem <float>[kMG]    maximum memory to use [768M]
-    -o, --output-file <file>      output file name [stdout]
-    -O, --output-type <b|u|z|v>   b: compressed BCF, u: uncompressed BCF, z: compressed VCF, v: uncompressed VCF [v]
-    -T, --temp-dir <dir>          temporary files [/tmp/bcftools-sort.XXXXXX/]
+    -m, --max-mem FLOAT[kMG]       maximum memory to use [768M]
+    -o, --output FILE              output file name [stdout]
+    -O, --output-type b|u|z|v      b: compressed BCF, u: uncompressed BCF, z: compressed VCF, v: uncompressed VCF [v]
+    -O, --output-type u|b|v|z[0-9] u/b: un/compressed BCF, v/z: un/compressed VCF, 0-9: compression level [v]
+    -T, --temp-dir DIR             temporary files [/tmp/bcftools.XXXXXX]