diff --git a/src/server.c b/src/server.c
index 6e74bc24..318932de 100644
--- a/src/server.c
+++ b/src/server.c
@@ -82,7 +82,7 @@ static const struct option options[] = {{"port", required_argument, NULL, 'p'},
                                         {"version", no_argument, NULL, 'v'},
                                         {"help", no_argument, NULL, 'h'},
                                         {NULL, 0, 0, 0}};
-static const char *opt_string = "p:i:c:H:u:g:s:w:I:b:P:6aSC:K:A:Rt:T:Om:oBd:vh";
+static const char *opt_string = "p:i:U:c:H:u:g:s:w:I:b:P:6aSC:K:A:Rt:T:Om:oBd:vh";
 
 static void print_help() {
   // clang-format off