diff --git a/config.c b/config.c
index 8db9c77098..c2d56309dc 100644
--- a/config.c
+++ b/config.c
@@ -1747,11 +1747,22 @@ static int do_git_config_sequence(const struct config_options *opts,
 		ret += git_config_from_file(fn, repo_config, data);
 
 	current_parsing_scope = CONFIG_SCOPE_WORKTREE;
-	if (!opts->ignore_worktree && repository_format_worktree_config) {
-		char *path = git_pathdup("config.worktree");
-		if (!access_or_die(path, R_OK, 0))
-			ret += git_config_from_file(fn, path, data);
-		free(path);
+	if (!opts->ignore_worktree && repo_config && opts->git_dir) {
+		struct repository_format repo_fmt = REPOSITORY_FORMAT_INIT;
+		struct strbuf buf = STRBUF_INIT;
+
+		read_repository_format(&repo_fmt, repo_config);
+
+		if (!verify_repository_format(&repo_fmt, &buf) &&
+		    repo_fmt.worktree_config) {
+			char *path = mkpathdup("%s/config.worktree", opts->git_dir);
+			if (!access_or_die(path, R_OK, 0))
+				ret += git_config_from_file(fn, path, data);
+			free(path);
+		}
+
+		strbuf_release(&buf);
+		clear_repository_format(&repo_fmt);
 	}
 
 	current_parsing_scope = CONFIG_SCOPE_COMMAND;
diff --git a/t/helper/test-config.c b/t/helper/test-config.c
index 61da2574c5..284f83a921 100644
--- a/t/helper/test-config.c
+++ b/t/helper/test-config.c
@@ -2,12 +2,19 @@
 #include "cache.h"
 #include "config.h"
 #include "string-list.h"
+#include "submodule-config.h"
 
 /*
  * This program exposes the C API of the configuration mechanism
  * as a set of simple commands in order to facilitate testing.
  *
- * Reads stdin and prints result of command to stdout:
+ * Usage: test-tool config [--submodule=<path>] <cmd> [<args>]
+ *
+ * If --submodule=<path> is given, <cmd> will operate on the submodule at the
+ * given <path>. This option is not valid for the commands: read_early_config,
+ * configset_get_value and configset_get_value_multi.
+ *
+ * Possible cmds are:
  *
  * get_value -> prints the value with highest priority for the entered key
  *
@@ -86,6 +93,8 @@ int cmd__config(int argc, const char **argv)
 	const struct string_list *strptr;
 	struct config_set cs = { .hash_initialized = 0 };
 	enum test_config_exit_code ret = TC_SUCCESS;
+	struct repository *repo = the_repository;
+	const char *subrepo_path = NULL;
 
 	argc--; /* skip over "config" */
 	argv++;
@@ -93,7 +102,18 @@ int cmd__config(int argc, const char **argv)
 	if (argc == 0)
 		goto print_usage_error;
 
+	if (skip_prefix(*argv, "--submodule=", &subrepo_path)) {
+		argc--;
+		argv++;
+		if (argc == 0)
+			goto print_usage_error;
+	}
+
 	if (argc == 2 && !strcmp(argv[0], "read_early_config")) {
+		if (subrepo_path) {
+			fprintf(stderr, "Cannot use --submodule with read_early_config\n");
+			return TC_USAGE_ERROR;
+		}
 		read_early_config(early_config_cb, (void *)argv[1]);
 		return TC_SUCCESS;
 	}
@@ -101,8 +121,23 @@ int cmd__config(int argc, const char **argv)
 	setup_git_directory();
 	git_configset_init(&cs);
 
+	if (subrepo_path) {
+		const struct submodule *sub;
+		struct repository *subrepo = xcalloc(1, sizeof(*repo));
+
+		sub = submodule_from_path(the_repository, &null_oid, subrepo_path);
+		if (!sub || repo_submodule_init(subrepo, the_repository, sub)) {
+			fprintf(stderr, "Invalid argument to --submodule: '%s'\n",
+				subrepo_path);
+			free(subrepo);
+			ret = TC_USAGE_ERROR;
+			goto out;
+		}
+		repo = subrepo;
+	}
+
 	if (argc == 2 && !strcmp(argv[0], "get_value")) {
-		if (!git_config_get_value(argv[1], &v)) {
+		if (!repo_config_get_value(repo, argv[1], &v)) {
 			if (!v)
 				printf("(NULL)\n");
 			else
@@ -112,7 +147,7 @@ int cmd__config(int argc, const char **argv)
 			ret = TC_VALUE_NOT_FOUND;
 		}
 	} else if (argc == 2 && !strcmp(argv[0], "get_value_multi")) {
-		strptr = git_config_get_value_multi(argv[1]);
+		strptr = repo_config_get_value_multi(repo, argv[1]);
 		if (strptr) {
 			for (i = 0; i < strptr->nr; i++) {
 				v = strptr->items[i].string;
@@ -126,27 +161,33 @@ int cmd__config(int argc, const char **argv)
 			ret = TC_VALUE_NOT_FOUND;
 		}
 	} else if (argc == 2 && !strcmp(argv[0], "get_int")) {
-		if (!git_config_get_int(argv[1], &val)) {
+		if (!repo_config_get_int(repo, argv[1], &val)) {
 			printf("%d\n", val);
 		} else {
 			printf("Value not found for \"%s\"\n", argv[1]);
 			ret = TC_VALUE_NOT_FOUND;
 		}
 	} else if (argc == 2 && !strcmp(argv[0], "get_bool")) {
-		if (!git_config_get_bool(argv[1], &val)) {
+		if (!repo_config_get_bool(repo, argv[1], &val)) {
 			printf("%d\n", val);
 		} else {
+
 			printf("Value not found for \"%s\"\n", argv[1]);
 			ret = TC_VALUE_NOT_FOUND;
 		}
 	} else if (argc == 2 && !strcmp(argv[0], "get_string")) {
-		if (!git_config_get_string_const(argv[1], &v)) {
+		if (!repo_config_get_string_const(repo, argv[1], &v)) {
 			printf("%s\n", v);
 		} else {
 			printf("Value not found for \"%s\"\n", argv[1]);
 			ret = TC_VALUE_NOT_FOUND;
 		}
 	} else if (argc >= 2 && !strcmp(argv[0], "configset_get_value")) {
+		if (subrepo_path) {
+			fprintf(stderr, "Cannot use --submodule with configset_get_value\n");
+			ret = TC_USAGE_ERROR;
+			goto out;
+		}
 		for (i = 2; i < argc; i++) {
 			int err;
 			if ((err = git_configset_add_file(&cs, argv[i]))) {
@@ -165,6 +206,11 @@ int cmd__config(int argc, const char **argv)
 			ret = TC_VALUE_NOT_FOUND;
 		}
 	} else if (argc >= 2 && !strcmp(argv[0], "configset_get_value_multi")) {
+		if (subrepo_path) {
+			fprintf(stderr, "Cannot use --submodule with configset_get_value_multi\n");
+			ret = TC_USAGE_ERROR;
+			goto out;
+		}
 		for (i = 2; i < argc; i++) {
 			int err;
 			if ((err = git_configset_add_file(&cs, argv[i]))) {
@@ -187,14 +233,19 @@ int cmd__config(int argc, const char **argv)
 			ret = TC_VALUE_NOT_FOUND;
 		}
 	} else if (!strcmp(argv[0], "iterate")) {
-		git_config(iterate_cb, NULL);
+		repo_config(repo, iterate_cb, NULL);
 	} else {
 print_usage_error:
-		fprintf(stderr, "Invalid syntax. Usage: test-tool config <cmd> [args]\n");
+		fprintf(stderr, "Invalid syntax. Usage: test-tool config"
+				" [--submodule=<path>] <cmd> [args]\n");
 		ret = TC_USAGE_ERROR;
 	}
 
 out:
 	git_configset_clear(&cs);
+	if (repo != the_repository) {
+		repo_clear(repo);
+		free(repo);
+	}
 	return ret;
 }
diff --git a/t/t2404-worktree-config.sh b/t/t2404-worktree-config.sh
index 286121d8de..b6ab793203 100755
--- a/t/t2404-worktree-config.sh
+++ b/t/t2404-worktree-config.sh
@@ -76,4 +76,20 @@ test_expect_success 'config.worktree no longer read without extension' '
 	test_cmp_config -C wt2 shared this.is
 '
 
+test_expect_success 'correctly read config.worktree from submodules' '
+	test_unconfig extensions.worktreeConfig &&
+	git init sub &&
+	(
+		cd sub &&
+		test_commit A &&
+		git config extensions.worktreeConfig true &&
+		git config --worktree wtconfig.sub test-value
+	) &&
+	git submodule add ./sub &&
+	git commit -m "add sub" &&
+	echo test-value >expect &&
+	test-tool config --submodule=sub get_value wtconfig.sub >actual &&
+	test_cmp expect actual
+'
+
 test_done