diff --git a/src/glue_utils/options.py b/src/glue_utils/options.py
index 83abe43..1d2b421 100644
--- a/src/glue_utils/options.py
+++ b/src/glue_utils/options.py
@@ -3,9 +3,8 @@
 from __future__ import annotations
 
 import sys
-from dataclasses import dataclass, fields
+from dataclasses import Field, dataclass, fields
 from typing import Any, get_type_hints
-from warnings import warn
 
 from awsglue.utils import getResolvedOptions
 from typing_extensions import Self
@@ -15,20 +14,21 @@ class UnsupportedTypeWarning(UserWarning):
     """Warning for unsupported field types."""
 
 
+class UnsupportedTypeError(TypeError):
+    """Error raised when field type is not supported."""
+
+
 @dataclass
 class BaseOptions:
     """Dataclass for storing resolved options."""
 
     @classmethod
     def __init_subclass__(cls) -> None:
-        """Warn if fields are not strings."""
+        """Raise error when using unsupported types."""
         for name, type_hint in get_type_hints(cls).items():
-            if type_hint is not str:
-                warn(
-                    f'"{name}" value is a string at runtime even if annotated to be "{type_hint}".',
-                    UnsupportedTypeWarning,
-                    stacklevel=2,
-                )
+            if type_hint not in cls.SUPPORTED_TYPES:
+                msg = f"Field {name} has unsupported type annotation: {type_hint}"
+                raise UnsupportedTypeError(msg)
         super().__init_subclass__()
 
     @classmethod
@@ -51,3 +51,36 @@ def from_options(cls, options: dict[str, Any] | None = None) -> Self:
         return cls(
             **{key: value for key, value in options.items() if key in field_names},
         )
+
+    def __post_init__(self) -> None:
+        """Convert field values to their annotated types."""
+        type_hints = get_type_hints(self)
+
+        for field in fields(self):
+            value = getattr(self, field.name)
+            target_type = type_hints.get(field.name, Any)
+
+            if not isinstance(value, target_type):
+                self._convert_and_set_field_value(field, value, target_type)
+
+    def _convert_and_set_field_value(
+        self,
+        field: Field[Any],
+        value: Any,  # noqa: ANN401
+        target_type: type,
+    ) -> None:
+        """Convert and set the field value to the target type."""
+        if target_type not in {str, int, float, bool}:
+            msg = f"Field {field.name} has unsupported type annotation: {target_type}"
+            raise UnsupportedTypeError(msg)
+
+        try:
+            if target_type is bool:
+                # Special handling for boolean strings
+                converted = str(value).lower() in ("true", "t", "yes", "y", "1")
+            else:
+                converted = target_type(value)
+            setattr(self, field.name, converted)
+        except (ValueError, TypeError) as e:
+            msg = f"Could not convert field {field.name} value '{value}' to {target_type.__name__}"
+            raise ValueError(msg) from e