diff --git a/parse-options.c b/parse-options.c
index 5224203ffe..6d9fc7bdc7 100644
--- a/parse-options.c
+++ b/parse-options.c
@@ -5,6 +5,7 @@
 #include "gettext.h"
 #include "strbuf.h"
 #include "string-list.h"
+#include "strmap.h"
 #include "utf8.h"
 
 static int disallow_abbreviated_options;
@@ -634,6 +635,7 @@ static void check_typos(const char *arg, const struct option *options)
 static void parse_options_check(const struct option *opts)
 {
 	char short_opts[128];
+	bool saw_number_option = false;
 	void *subcommand_value = NULL;
 
 	memset(short_opts, '\0', sizeof(short_opts));
@@ -648,6 +650,11 @@ static void parse_options_check(const struct option *opts)
 			else if (short_opts[opts->short_name]++)
 				optbug(opts, "short name already used");
 		}
+		if (opts->type == OPTION_NUMBER) {
+			if (saw_number_option)
+				optbug(opts, "duplicate numerical option");
+			saw_number_option = true;
+		}
 		if (opts->flags & PARSE_OPT_NODASH &&
 		    ((opts->flags & PARSE_OPT_OPTARG) ||
 		     !(opts->flags & PARSE_OPT_NOARG) ||
@@ -707,6 +714,20 @@ static void parse_options_check(const struct option *opts)
 	BUG_if_bug("invalid 'struct option'");
 }
 
+static void parse_options_check_harder(const struct option *opts)
+{
+	struct strset long_names = STRSET_INIT;
+
+	for (; opts->type != OPTION_END; opts++) {
+		if (opts->long_name) {
+			if (!strset_add(&long_names, opts->long_name))
+				optbug(opts, "long name already used");
+		}
+	}
+	BUG_if_bug("invalid 'struct option'");
+	strset_clear(&long_names);
+}
+
 static int has_subcommands(const struct option *options)
 {
 	for (; options->type != OPTION_END; options++)
@@ -1324,6 +1345,8 @@ static enum parse_opt_result usage_with_options_internal(struct parse_opt_ctx_t
 	const char *prefix = usage_prefix;
 	int saw_empty_line = 0;
 
+	parse_options_check_harder(opts);
+
 	if (!usagestr)
 		return PARSE_OPT_HELP;