calibrate_detector: Add missing item from --help

1 files changed, 2 insertions, 1 deletions

diff --git a/src/calibrate_detector.c b/src/calibrate_detector.c
index 8902ea87..b291ecc2 100644
--- a/src/calibrate_detector.c
+++ b/src/calibrate_detector.c
@@ -91,7 +91,8 @@ static void show_help(const char *s)
 "                           pixels in each 3x3 region to zero if any of them\n"
 "                           have negative values.\n"
 "\n"
-"  -j <n>                  Run <n> analyses in parallel.  Default 1.\n");
+"  -j <n>                  Run <n> analyses in parallel.  Default 1.\n"
+" -x, --prefix=<p>         Prefix filenames from input file with 'p'.\n");
 }