diff --git a/end_to_end_tests/golden-record/my_test_api_client/models/__init__.py b/end_to_end_tests/golden-record/my_test_api_client/models/__init__.py
index e6e8275f8..85e5243ec 100644
--- a/end_to_end_tests/golden-record/my_test_api_client/models/__init__.py
+++ b/end_to_end_tests/golden-record/my_test_api_client/models/__init__.py
@@ -23,6 +23,7 @@
 from .import_ import Import
 from .model_from_all_of import ModelFromAllOf
 from .model_name import ModelName
+from .model_reference_with_periods import ModelReferenceWithPeriods
 from .model_with_additional_properties_inlined import ModelWithAdditionalPropertiesInlined
 from .model_with_additional_properties_inlined_additional_property import (
     ModelWithAdditionalPropertiesInlinedAdditionalProperty,
diff --git a/end_to_end_tests/golden-record/my_test_api_client/models/model_reference_with_periods.py b/end_to_end_tests/golden-record/my_test_api_client/models/model_reference_with_periods.py
new file mode 100644
index 000000000..15bab8de5
--- /dev/null
+++ b/end_to_end_tests/golden-record/my_test_api_client/models/model_reference_with_periods.py
@@ -0,0 +1,44 @@
+from typing import Any, Dict, List, Type, TypeVar
+
+import attr
+
+T = TypeVar("T", bound="ModelReferenceWithPeriods")
+
+
+@attr.s(auto_attribs=True)
+class ModelReferenceWithPeriods:
+    """A Model with periods in its reference"""
+
+    additional_properties: Dict[str, Any] = attr.ib(init=False, factory=dict)
+
+    def to_dict(self) -> Dict[str, Any]:
+
+        field_dict: Dict[str, Any] = {}
+        field_dict.update(self.additional_properties)
+        field_dict.update({})
+
+        return field_dict
+
+    @classmethod
+    def from_dict(cls: Type[T], src_dict: Dict[str, Any]) -> T:
+        d = src_dict.copy()
+        model_reference_with_periods = cls()
+
+        model_reference_with_periods.additional_properties = d
+        return model_reference_with_periods
+
+    @property
+    def additional_keys(self) -> List[str]:
+        return list(self.additional_properties.keys())
+
+    def __getitem__(self, key: str) -> Any:
+        return self.additional_properties[key]
+
+    def __setitem__(self, key: str, value: Any) -> None:
+        self.additional_properties[key] = value
+
+    def __delitem__(self, key: str) -> None:
+        del self.additional_properties[key]
+
+    def __contains__(self, key: str) -> bool:
+        return key in self.additional_properties
diff --git a/end_to_end_tests/openapi.json b/end_to_end_tests/openapi.json
index 4131446a9..22e095511 100644
--- a/end_to_end_tests/openapi.json
+++ b/end_to_end_tests/openapi.json
@@ -1902,6 +1902,10 @@
       },
       "None":  {
         "type": "object"
+      },
+      "model.reference.with.Periods": {
+        "type": "object",
+        "description": "A Model with periods in its reference"
       }
     }
   }
diff --git a/openapi_python_client/utils.py b/openapi_python_client/utils.py
index 223739011..cb1ac611c 100644
--- a/openapi_python_client/utils.py
+++ b/openapi_python_client/utils.py
@@ -3,7 +3,7 @@
 from keyword import iskeyword
 from typing import Any, List
 
-DELIMITERS = " _-"
+DELIMITERS = r"\. _-"
 
 
 class PythonIdentifier(str):
diff --git a/tests/test_utils.py b/tests/test_utils.py
index 2345aaee8..97f0bee2a 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -47,6 +47,7 @@ def test_empty_is_prefixed(self):
         ("Response200Okay", ["Response", "200", "Okay"]),
         ("S3Config", ["S3", "Config"]),
         ("s3config", ["s3config"]),
+        ("fully.qualified.Name", ["fully", "qualified", "Name"]),
     ],
 )
 def test_split_words(before, after):
@@ -83,8 +84,8 @@ def test_kebab_case():
     assert utils.kebab_case("keep_alive") == "keep-alive"
 
 
-def test__sanitize():
-    assert utils.sanitize("something*~with lots_- of weird things}=") == "somethingwith lots_- of weird things"
+def test_sanitize():
+    assert utils.sanitize("some.thing*~with lots_- of weird things}=") == "some.thingwith lots_- of weird things"
 
 
 def test_no_string_escapes():