diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index 8127228..4e4dac1 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -10,6 +10,8 @@
   usage text now uses ASCII metavariables such as `<user>` and `<message>`.
 - Standardized user-facing `:msg` / `:inbox` terminology around "private
   message" / "私信" instead of mixing it with "whisper" wording.
+- Kept localized startup CLI syntax stable by using `用法: tnt [options]`
+  instead of localizing the `[options]` metavariable.
 - Renamed the internal language state from help-oriented names to
   UI-language names (`ui_lang_t`, `client->ui_lang`, and
   `i18n_*_ui_lang`) so future i18n work has a correctly named seam.
diff --git a/src/cli_text.c b/src/cli_text.c
index 87f8249..6c2802f 100644
--- a/src/cli_text.c
+++ b/src/cli_text.c
@@ -9,7 +9,7 @@ void cli_text_append_help(char *buffer, size_t buf_size, size_t *pos,
     if (lang == UI_LANG_ZH) {
         buffer_appendf(buffer, buf_size, pos,
                        "tnt %s - 匿名 SSH 聊天服务器\n\n"
-                       "用法: %s [选项]\n\n"
+                       "用法: %s [options]\n\n"
                        "选项:\n"
                        "  -p, --port PORT       监听 PORT (默认: %d)\n"
                        "  -d, --state-dir DIR   将主机密钥和日志存放在 DIR\n"
diff --git a/tests/unit/test_cli_text.c b/tests/unit/test_cli_text.c
index ff972a6..048f504 100644
--- a/tests/unit/test_cli_text.c
+++ b/tests/unit/test_cli_text.c
@@ -28,7 +28,8 @@ TEST(help_matches_language) {
     pos = 0;
     cli_text_append_help(output, sizeof(output), &pos, "tnt", UI_LANG_ZH);
     assert(strstr(output, "匿名 SSH 聊天服务器") != NULL);
-    assert(strstr(output, "用法: tnt [选项]") != NULL);
+    assert(strstr(output, "用法: tnt [options]") != NULL);
+    assert(strstr(output, "[选项]") == NULL);
     assert(strstr(output, "TNT_LANG") != NULL);
 }
 
diff --git a/tests/unit/test_command_catalog.c b/tests/unit/test_command_catalog.c
index dce3e40..5445a9c 100644
--- a/tests/unit/test_command_catalog.c
+++ b/tests/unit/test_command_catalog.c
@@ -1,6 +1,7 @@
 /* Unit tests for command catalog names, aliases, and generated help text */
 
 #include "../../include/command_catalog.h"
+#include "text_assert.h"
 #include <assert.h>
 #include <stdio.h>
 #include <string.h>
@@ -77,6 +78,7 @@ TEST(generates_localized_help_sections) {
     assert(strstr(zh, "<用户>") == NULL);
     assert(strstr(zh, "<消息>") == NULL);
     assert(strstr(zh, ":support") == NULL);
+    assert_ascii_angle_placeholders(zh);
 }
 
 int main(void) {
diff --git a/tests/unit/test_help_text.c b/tests/unit/test_help_text.c
index 1bc3a0d..7589746 100644
--- a/tests/unit/test_help_text.c
+++ b/tests/unit/test_help_text.c
@@ -1,6 +1,7 @@
 /* Unit tests for help text ownership and language selection */
 
 #include "../../include/help_text.h"
+#include "text_assert.h"
 #include <assert.h>
 #include <stdio.h>
 #include <string.h>
@@ -43,6 +44,7 @@ TEST(full_help_matches_language) {
     assert(strstr(zh, ":support") == NULL);
     assert(strstr(zh, ":commands") == NULL);
     assert(strstr(zh, "切换英文/中文") != NULL);
+    assert_ascii_angle_placeholders(zh);
 }
 
 int main(void) {
diff --git a/tests/unit/test_i18n.c b/tests/unit/test_i18n.c
index 7870f6a..e2f6a82 100644
--- a/tests/unit/test_i18n.c
+++ b/tests/unit/test_i18n.c
@@ -1,6 +1,7 @@
 /* Unit tests for i18n language selection and text lookup */
 
 #include "../../include/i18n.h"
+#include "text_assert.h"
 #include <assert.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -164,6 +165,8 @@ TEST(text_catalog_is_complete) {
     for (int id = 0; id < I18N_TEXT_COUNT; id++) {
         assert(i18n_text(UI_LANG_EN, (i18n_text_id_t)id)[0] != '\0');
         assert(i18n_text(UI_LANG_ZH, (i18n_text_id_t)id)[0] != '\0');
+        assert_ascii_angle_placeholders(
+            i18n_text(UI_LANG_ZH, (i18n_text_id_t)id));
     }
 
     assert(strcmp(i18n_text(UI_LANG_EN,
diff --git a/tests/unit/test_manual_text.c b/tests/unit/test_manual_text.c
index 47b8730..cec002d 100644
--- a/tests/unit/test_manual_text.c
+++ b/tests/unit/test_manual_text.c
@@ -1,6 +1,7 @@
 /* Unit tests for concise manual text language selection */
 
 #include "../../include/manual_text.h"
+#include "text_assert.h"
 #include <assert.h>
 #include <stdio.h>
 #include <string.h>
@@ -58,6 +59,7 @@ TEST(interactive_manual_matches_language) {
     assert(strstr(zh, ":support") == NULL);
     assert(strstr(zh, ":commands") == NULL);
     assert(count_lines(zh) <= 20);
+    assert_ascii_angle_placeholders(zh);
 }
 
 int main(void) {
diff --git a/tests/unit/text_assert.h b/tests/unit/text_assert.h
new file mode 100644
index 0000000..14e16cd
--- /dev/null
+++ b/tests/unit/text_assert.h
@@ -0,0 +1,24 @@
+#ifndef TEST_TEXT_ASSERT_H
+#define TEST_TEXT_ASSERT_H
+
+#include <assert.h>
+
+static void assert_ascii_angle_placeholders(const char *text) {
+    int in_placeholder = 0;
+
+    while (text && *text) {
+        unsigned char ch = (unsigned char)*text;
+
+        if (ch == '<') {
+            in_placeholder = 1;
+        } else if (ch == '>') {
+            in_placeholder = 0;
+        } else if (in_placeholder) {
+            assert(ch < 128);
+        }
+
+        text++;
+    }
+}
+
+#endif /* TEST_TEXT_ASSERT_H */