diff --git a/outlines/fsm/types.py b/outlines/fsm/types.py
index cddcd163f..5695dee07 100644
--- a/outlines/fsm/types.py
+++ b/outlines/fsm/types.py
@@ -32,10 +32,12 @@ def custom_format_fn(sequence: str) -> Any:
 
     if isinstance(python_type, EnumMeta):
         values = python_type.__members__.keys()
-        regex_str = "(" + "|".join(values) + ")"
-        format_fn = lambda x: str(x)
+        enum_regex_str: str = "(" + "|".join(values) + ")"
 
-        return regex_str, format_fn
+        def enum_format_fn(sequence: str) -> str:
+            return str(sequence)
+
+        return enum_regex_str, enum_format_fn
 
     if python_type == float:
 
diff --git a/outlines/types/__init__.py b/outlines/types/__init__.py
index 7af7f296f..266d3a68e 100644
--- a/outlines/types/__init__.py
+++ b/outlines/types/__init__.py
@@ -1,4 +1,4 @@
+from . import airports, countries
 from .isbn import ISBN
 from .phone_numbers import PhoneNumber
 from .zip_codes import ZipCode
-from . import airports
diff --git a/pyproject.toml b/pyproject.toml
index c4d29142d..8a7cc1460 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -126,6 +126,7 @@ module = [
     "vllm.*",
     "uvicorn.*",
     "fastapi.*",
+    "pycountry.*",
     "pyairports.*",
 ]
 ignore_missing_imports = true
diff --git a/tests/test_types.py b/tests/test_types.py
index 8143d3d6d..2391ccc18 100644
--- a/tests/test_types.py
+++ b/tests/test_types.py
@@ -47,10 +47,19 @@ class Model(BaseModel):
     [
         (types.airports.IATA, "CDG", True),
         (types.airports.IATA, "XXX", False),
+        (types.countries.Alpha2, "FR", True),
+        (types.countries.Alpha2, "XX", False),
+        (types.countries.Alpha3, "UKR", True),
+        (types.countries.Alpha3, "XXX", False),
+        (types.countries.Numeric, "004", True),
+        (types.countries.Numeric, "900", False),
+        (types.countries.Name, "Ukraine", True),
+        (types.countries.Name, "Wonderland", False),
+        (types.countries.Flag, "🇿🇼", True),
+        (types.countries.Flag, "🤗", False),
     ],
 )
 def test_type_enum(custom_type, test_string, should_match):
-
     type_name = custom_type.__name__
 
     class Model(BaseModel):