diff --git a/config.c b/config.c
index 84ff34685..2567b546a 100644
--- a/config.c
+++ b/config.c
@@ -858,7 +858,7 @@ int git_config_early(config_fn_t fn, void *data, const char *repo_config)
 
 	switch (git_config_from_parameters(fn, data)) {
 	case -1: /* error */
-		ret--;
+		die("unable to parse command-line config");
 		break;
 	case 0: /* found nothing */
 		break;
diff --git a/t/t1300-repo-config.sh b/t/t1300-repo-config.sh
index ca5058e0d..584e956ac 100755
--- a/t/t1300-repo-config.sh
+++ b/t/t1300-repo-config.sh
@@ -910,4 +910,12 @@ test_expect_success 'git -c does not split values on equals' '
 	test_cmp expect actual
 '
 
+test_expect_success 'git -c dies on bogus config' '
+	test_must_fail git -c core.bare=foo rev-parse
+'
+
+test_expect_success 'git -c complains about empty key' '
+	test_must_fail git -c "=foo" rev-parse
+'
+
 test_done