diff --git a/joj3_config_generator/models/repo.py b/joj3_config_generator/models/repo.py
index 87734a9..18512dd 100644
--- a/joj3_config_generator/models/repo.py
+++ b/joj3_config_generator/models/repo.py
@@ -50,8 +50,8 @@ class HealthCheck(StrictBaseModel):
     required_files: List[str] = Field(
         [], validation_alias=AliasChoices("required-files", "required_files")
     )
-    whitelisted_chars: List[str] = Field(
-        [], validation_alias=AliasChoices("whitelisted-chars", "whitelisted_chars")
+    whitelisted_chars: str = Field(
+        "", validation_alias=AliasChoices("whitelisted-chars", "whitelisted_chars")
     )
 
     @field_validator("max_size", mode="before")
@@ -63,12 +63,8 @@ class HealthCheck(StrictBaseModel):
 
     @field_validator("whitelisted_chars")
     @classmethod
-    def ensure_non_ascii_single_char_list(cls, chars: List[str]) -> List[str]:
+    def ensure_non_ascii_chars(cls, chars: str) -> str:
         for c in chars:
-            if len(c) != 1:
-                raise ValueError(
-                    "Each whitelisted character must be exactly one character"
-                )
             if c.isascii():
                 raise ValueError(
                     "Each whitelisted character must be a non-ASCII character"
diff --git a/joj3_config_generator/transformers/repo.py b/joj3_config_generator/transformers/repo.py
index d5749fc..82f0f93 100644
--- a/joj3_config_generator/transformers/repo.py
+++ b/joj3_config_generator/transformers/repo.py
@@ -131,7 +131,7 @@ def get_health_check_args(repo_conf: repo.Config) -> List[str]:
     ]
     if repo_conf.health_check.whitelisted_chars:
         args.append(
-            f"-whitelistedChars={','.join(repo_conf.health_check.whitelisted_chars)}"
+            f"-whitelistedChars={','.join(list(repo_conf.health_check.whitelisted_chars))}"
         )
     args.extend(
         [
diff --git a/tests/convert/whitelisted-chars/repo.toml b/tests/convert/whitelisted-chars/repo.toml
index b62e42b..bd66ab0 100644
--- a/tests/convert/whitelisted-chars/repo.toml
+++ b/tests/convert/whitelisted-chars/repo.toml
@@ -1 +1 @@
-health-check.whitelisted-chars = ["你", "好", "！"]
+health-check.whitelisted-chars = "你好！"