diff --git a/src/python/flowmetal/parser.py b/src/python/flowmetal/parser.py
index 1032b2d..0492676 100644
--- a/src/python/flowmetal/parser.py
+++ b/src/python/flowmetal/parser.py
@@ -41,13 +41,11 @@ class TokenBase(object):
         """The raw token as scanned."""
 
 
-class ConstTokenBase(TokenBase):
+class ConstTokenBase(TokenBase, NamedTuple):
     """The shared interface for constant tokens"""
-
-    @property
-    @abstractmethod
-    def data(self) -> Any:
-        """The value of the token."""
+    data: Any
+    raw: str
+    pos: Position
 
     # Hash according to data
     def __hash__(self):
@@ -64,53 +62,32 @@ class ConstTokenBase(TokenBase):
         return self.data > other
 
 
-class BooleanToken(ConstTokenBase, Enum):
+class BooleanToken(ConstTokenBase):
     """A read boolean."""
-    data: bool
-    raw: str
-    pos: Position
 
 
-class IntegerToken(ConstTokenBase, NamedTuple):
+class IntegerToken(ConstTokenBase):
     """A read integer, including position."""
-    data: int
-    raw: str
-    pos: Position
 
 
-class FractionToken(ConstTokenBase, NamedTuple):
+class FractionToken(ConstTokenBase):
     """A read fraction, including position."""
-    data: Fraction
-    raw: str
-    pos: Position
 
 
-class FloatToken(ConstTokenBase, NamedTuple):
+class FloatToken(ConstTokenBase):
     """A read floating point number, including position."""
-    data: float
-    raw: str
-    pos: Position
 
 
-class SymbolToken(ConstTokenBase, NamedTuple):
+class SymbolToken(ConstTokenBase):
     """A read symbol, including position."""
-    data: str
-    raw: str
-    pos: Position
 
 
-class KeywordToken(ConstTokenBase, NamedTuple):
+class KeywordToken(ConstTokenBase):
     """A read keyword."""
-    data: str
-    raw: str
-    pos: Position
 
 
-class StringToken(ConstTokenBase, NamedTuple):
+class StringToken(ConstTokenBase):
     """A read string, including position."""
-    data: str
-    raw: str
-    pos: Position
 
 
 class ListType(Enum):