diff --git a/parse-options.c b/parse-options.c
index 093eaf2..e0c94b0 100644
--- a/parse-options.c
+++ b/parse-options.c
@@ -70,42 +70,10 @@ static void fix_filename(const char *prefix, char **file)
 		*file = prefix_filename_except_for_dash(prefix, *file);
 }
 
-static enum parse_opt_result opt_command_mode_error(
-	const struct option *opt,
-	const struct option *all_opts,
-	enum opt_parsed flags)
-{
-	const struct option *that;
-	struct strbuf that_name = STRBUF_INIT;
-
-	/*
-	 * Find the other option that was used to set the variable
-	 * already, and report that this is not compatible with it.
-	 */
-	for (that = all_opts; that->type != OPTION_END; that++) {
-		if (that == opt ||
-		    !(that->flags & PARSE_OPT_CMDMODE) ||
-		    that->value != opt->value ||
-		    that->defval != *(int *)opt->value)
-			continue;
-
-		if (that->long_name)
-			strbuf_addf(&that_name, "--%s", that->long_name);
-		else
-			strbuf_addf(&that_name, "-%c", that->short_name);
-		error(_("%s is incompatible with %s"),
-		      optname(opt, flags), that_name.buf);
-		strbuf_release(&that_name);
-		return PARSE_OPT_ERROR;
-	}
-	return error(_("%s : incompatible with something else"),
-		     optname(opt, flags));
-}
-
-static enum parse_opt_result get_value(struct parse_opt_ctx_t *p,
-				       const struct option *opt,
-				       const struct option *all_opts,
-				       enum opt_parsed flags)
+static enum parse_opt_result do_get_value(struct parse_opt_ctx_t *p,
+					  const struct option *opt,
+					  enum opt_parsed flags,
+					  const char **argp)
 {
 	const char *s, *arg;
 	const int unset = flags & OPT_UNSET;
@@ -118,14 +86,6 @@ static enum parse_opt_result get_value(struct parse_opt_ctx_t *p,
 	if (!(flags & OPT_SHORT) && p->opt && (opt->flags & PARSE_OPT_NOARG))
 		return error(_("%s takes no value"), optname(opt, flags));
 
-	/*
-	 * Giving the same mode option twice, although unnecessary,
-	 * is not a grave error, so let it pass.
-	 */
-	if ((opt->flags & PARSE_OPT_CMDMODE) &&
-	    *(int *)opt->value && *(int *)opt->value != opt->defval)
-		return opt_command_mode_error(opt, all_opts, flags);
-
 	switch (opt->type) {
 	case OPTION_LOWLEVEL_CALLBACK:
 		return opt->ll_callback(p, opt, NULL, unset);
@@ -200,6 +160,8 @@ static enum parse_opt_result get_value(struct parse_opt_ctx_t *p,
 			p_unset = 0;
 			p_arg = arg;
 		}
+		if (opt->flags & PARSE_OPT_CMDMODE)
+			*argp = p_arg;
 		if (opt->callback)
 			return (*opt->callback)(opt, p_arg, p_unset) ? (-1) : 0;
 		else
@@ -247,16 +209,91 @@ static enum parse_opt_result get_value(struct parse_opt_ctx_t *p,
 	}
 }
 
+struct parse_opt_cmdmode_list {
+	int value, *value_ptr;
+	const struct option *opt;
+	const char *arg;
+	enum opt_parsed flags;
+	struct parse_opt_cmdmode_list *next;
+};
+
+static void build_cmdmode_list(struct parse_opt_ctx_t *ctx,
+			       const struct option *opts)
+{
+	ctx->cmdmode_list = NULL;
+
+	for (; opts->type != OPTION_END; opts++) {
+		struct parse_opt_cmdmode_list *elem = ctx->cmdmode_list;
+		int *value_ptr = opts->value;
+
+		if (!(opts->flags & PARSE_OPT_CMDMODE) || !value_ptr)
+			continue;
+
+		while (elem && elem->value_ptr != value_ptr)
+			elem = elem->next;
+		if (elem)
+			continue;
+
+		CALLOC_ARRAY(elem, 1);
+		elem->value_ptr = value_ptr;
+		elem->value = *value_ptr;
+		elem->next = ctx->cmdmode_list;
+		ctx->cmdmode_list = elem;
+	}
+}
+
+static char *optnamearg(const struct option *opt, const char *arg,
+			enum opt_parsed flags)
+{
+	if (flags & OPT_SHORT)
+		return xstrfmt("-%c%s", opt->short_name, arg ? arg : "");
+	return xstrfmt("--%s%s%s%s", flags & OPT_UNSET ? "no-" : "",
+		       opt->long_name, arg ? "=" : "", arg ? arg : "");
+}
+
+static enum parse_opt_result get_value(struct parse_opt_ctx_t *p,
+				       const struct option *opt,
+				       enum opt_parsed flags)
+{
+	const char *arg = NULL;
+	enum parse_opt_result result = do_get_value(p, opt, flags, &arg);
+	struct parse_opt_cmdmode_list *elem = p->cmdmode_list;
+	char *opt_name, *other_opt_name;
+
+	for (; elem; elem = elem->next) {
+		if (*elem->value_ptr == elem->value)
+			continue;
+
+		if (elem->opt &&
+		    (elem->opt->flags | opt->flags) & PARSE_OPT_CMDMODE)
+			break;
+
+		elem->opt = opt;
+		elem->arg = arg;
+		elem->flags = flags;
+		elem->value = *elem->value_ptr;
+	}
+
+	if (result || !elem)
+		return result;
+
+	opt_name = optnamearg(opt, arg, flags);
+	other_opt_name = optnamearg(elem->opt, elem->arg, elem->flags);
+	error(_("%s is incompatible with %s"), opt_name, other_opt_name);
+	free(opt_name);
+	free(other_opt_name);
+	return -1;
+}
+
 static enum parse_opt_result parse_short_opt(struct parse_opt_ctx_t *p,
 					     const struct option *options)
 {
-	const struct option *all_opts = options;
 	const struct option *numopt = NULL;
 
 	for (; options->type != OPTION_END; options++) {
 		if (options->short_name == *p->opt) {
 			p->opt = p->opt[1] ? p->opt + 1 : NULL;
-			return get_value(p, options, all_opts, OPT_SHORT);
+			return get_value(p, options, OPT_SHORT);
 		}
 
 		/*
@@ -318,7 +355,6 @@ static enum parse_opt_result parse_long_opt(
 	struct parse_opt_ctx_t *p, const char *arg,
 	const struct option *options)
 {
-	const struct option *all_opts = options;
 	const char *arg_end = strchrnul(arg, '=');
 	const struct option *abbrev_option = NULL, *ambiguous_option = NULL;
 	enum opt_parsed abbrev_flags = OPT_LONG, ambiguous_flags = OPT_LONG;
@@ -387,7 +423,7 @@ static enum parse_opt_result parse_long_opt(
 				continue;
 			p->opt = rest + 1;
 		}
-		return get_value(p, options, all_opts, flags ^ opt_flags);
+		return get_value(p, options, flags ^ opt_flags);
 	}
 
 	if (disallow_abbreviated_options && (ambiguous_option || abbrev_option))
@@ -405,7 +441,7 @@ static enum parse_opt_result parse_long_opt(
 		return PARSE_OPT_HELP;
 	}
 	if (abbrev_option)
-		return get_value(p, abbrev_option, all_opts, abbrev_flags);
+		return get_value(p, abbrev_option, abbrev_flags);
 	return PARSE_OPT_UNKNOWN;
 }
 
@@ -413,13 +449,11 @@ static enum parse_opt_result parse_nodash_opt(struct parse_opt_ctx_t *p,
 					      const char *arg,
 					      const struct option *options)
 {
-	const struct option *all_opts = options;
-
 	for (; options->type != OPTION_END; options++) {
 		if (!(options->flags & PARSE_OPT_NODASH))
 			continue;
 		if (options->short_name == arg[0] && arg[1] == '\0')
-			return get_value(p, options, all_opts, OPT_SHORT);
+			return get_value(p, options, OPT_SHORT);
 	}
 	return PARSE_OPT_ERROR;
 }
@@ -574,6 +608,7 @@ static void parse_options_start_1(struct parse_opt_ctx_t *ctx,
 	    (flags & PARSE_OPT_KEEP_ARGV0))
 		BUG("Can't keep argv0 if you don't have it");
 	parse_options_check(options);
+	build_cmdmode_list(ctx, options);
 }
 
 void parse_options_start(struct parse_opt_ctx_t *ctx,
@@ -1006,6 +1041,11 @@ int parse_options(int argc, const char **argv,
 	precompose_argv_prefix(argc, argv, NULL);
 	free_preprocessed_options(real_options);
 	free(ctx.alias_groups);
+	for (struct parse_opt_cmdmode_list *elem = ctx.cmdmode_list; elem;) {
+		struct parse_opt_cmdmode_list *next = elem->next;
+		free(elem);
+		elem = next;
+	}
 	return parse_options_end(&ctx);
 }
 
diff --git a/parse-options.h b/parse-options.h
index 4a66ec3..bd62e20 100644
--- a/parse-options.h
+++ b/parse-options.h
@@ -445,6 +445,8 @@ static inline void die_for_incompatible_opt3(int opt1, const char *opt1_name,
 
 /*----- incremental advanced APIs -----*/
 
+struct parse_opt_cmdmode_list;
+
 /*
  * It's okay for the caller to consume argv/argc in the usual way.
  * Other fields of that structure are private to parse-options and should not
@@ -459,6 +461,7 @@ struct parse_opt_ctx_t {
 	unsigned has_subcommands;
 	const char *prefix;
 	const char **alias_groups; /* must be in groups of 3 elements! */
+	struct parse_opt_cmdmode_list *cmdmode_list;
 };
 
 void parse_options_start(struct parse_opt_ctx_t *ctx,
diff --git a/t/helper/test-parse-options.c b/t/helper/test-parse-options.c
index a4f6e24..ded8116 100644
--- a/t/helper/test-parse-options.c
+++ b/t/helper/test-parse-options.c
@@ -21,6 +21,19 @@ static struct {
 	int unset;
 } length_cb;
 
+static int mode34_callback(const struct option *opt, const char *arg, int unset)
+{
+	if (unset)
+		*(int *)opt->value = 0;
+	else if (!strcmp(arg, "3"))
+		*(int *)opt->value = 3;
+	else if (!strcmp(arg, "4"))
+		*(int *)opt->value = 4;
+	else
+		return error("invalid value for '%s': '%s'", "--mode34", arg);
+	return 0;
+}
+
 static int length_callback(const struct option *opt, const char *arg, int unset)
 {
 	length_cb.called = 1;
@@ -124,6 +137,9 @@ int cmd__parse_options(int argc, const char **argv)
 		OPT_SET_INT(0, "set23", &integer, "set integer to 23", 23),
 		OPT_CMDMODE(0, "mode1", &integer, "set integer to 1 (cmdmode option)", 1),
 		OPT_CMDMODE(0, "mode2", &integer, "set integer to 2 (cmdmode option)", 2),
+		OPT_CALLBACK_F(0, "mode34", &integer, "(3|4)",
+			"set integer to 3 or 4 (cmdmode option)",
+			PARSE_OPT_CMDMODE, mode34_callback),
 		OPT_CALLBACK('L', "length", &integer, "str",
 			"get length of <str>", length_callback),
 		OPT_FILENAME('F', "file", &file, "set file to <file>"),
diff --git a/t/t0040-parse-options.sh b/t/t0040-parse-options.sh
index a0ad619..06fb9e6 100755
--- a/t/t0040-parse-options.sh
+++ b/t/t0040-parse-options.sh
@@ -28,6 +28,7 @@
     --[no-]set23          set integer to 23
     --mode1               set integer to 1 (cmdmode option)
     --mode2               set integer to 2 (cmdmode option)
+    --[no-]mode34 (3|4)   set integer to 3 or 4 (cmdmode option)
     -L, --[no-]length <str>
                           get length of <str>
     -F, --[no-]file <file>
@@ -366,19 +367,41 @@
 '
 
 test_expect_success 'OPT_CMDMODE() works' '
-	test-tool parse-options --expect="integer: 1" --mode1
+	test-tool parse-options --expect="integer: 1" --mode1 &&
+	test-tool parse-options --expect="integer: 3" --mode34=3
 '
 
-test_expect_success 'OPT_CMDMODE() detects incompatibility' '
+test_expect_success 'OPT_CMDMODE() detects incompatibility (1)' '
 	test_must_fail test-tool parse-options --mode1 --mode2 >output 2>output.err &&
 	test_must_be_empty output &&
-	test_i18ngrep "incompatible with --mode" output.err
+	test_i18ngrep "mode1" output.err &&
+	test_i18ngrep "mode2" output.err &&
+	test_i18ngrep "is incompatible with" output.err
 '
 
-test_expect_success 'OPT_CMDMODE() detects incompatibility with something else' '
+test_expect_success 'OPT_CMDMODE() detects incompatibility (2)' '
 	test_must_fail test-tool parse-options --set23 --mode2 >output 2>output.err &&
 	test_must_be_empty output &&
-	test_i18ngrep "incompatible with something else" output.err
+	test_i18ngrep "mode2" output.err &&
+	test_i18ngrep "set23" output.err &&
+	test_i18ngrep "is incompatible with" output.err
+'
+
+test_expect_success 'OPT_CMDMODE() detects incompatibility (3)' '
+	test_must_fail test-tool parse-options --mode2 --set23 >output 2>output.err &&
+	test_must_be_empty output &&
+	test_i18ngrep "mode2" output.err &&
+	test_i18ngrep "set23" output.err &&
+	test_i18ngrep "is incompatible with" output.err
+'
+
+test_expect_success 'OPT_CMDMODE() detects incompatibility (4)' '
+	test_must_fail test-tool parse-options --mode2 --mode34=3 \
+		>output 2>output.err &&
+	test_must_be_empty output &&
+	test_i18ngrep "mode2" output.err &&
+	test_i18ngrep "mode34.3" output.err &&
+	test_i18ngrep "is incompatible with" output.err
 '
 
 test_expect_success 'OPT_COUNTUP() with PARSE_OPT_NODASH works' '