diff --git a/tools/jfjoch_process.cpp b/tools/jfjoch_process.cpp
index 664c86ee..41fb0de6 100644
--- a/tools/jfjoch_process.cpp
+++ b/tools/jfjoch_process.cpp
@@ -41,7 +41,7 @@ void print_usage(Logger &logger) {
     logger.Info("   -S<num>    Space group number");
     logger.Info("   -M         Scale and merge (refine mosaicity) and write scaled.hkl + image.dat");
     logger.Info("   -L         Use log-scaling residual");
-    logger.Info("   -m         Mosaicity refinement none|fixed|image (default: image)");
+    logger.Info("   -m<txt>    Mosaicity refinement none|fixed|image (default: image)");
 }
 
 int main(int argc, char **argv) {
@@ -76,7 +76,7 @@ int main(int argc, char **argv) {
     }
 
     int opt;
-    while ((opt = getopt(argc, argv, "o:N:s:e:vR::Fxd:S:M")) != -1) {
+    while ((opt = getopt(argc, argv, "o:N:s:e:vR::Fxd:S:MLm:")) != -1) {
         switch (opt) {
             case 'o':
                 output_prefix = optarg;