diff --git a/loopy/kernel/function_interface.py b/loopy/kernel/function_interface.py
index 40d9969bf..33dfd73f2 100644
--- a/loopy/kernel/function_interface.py
+++ b/loopy/kernel/function_interface.py
@@ -23,8 +23,8 @@
 THE SOFTWARE.
 """
 from abc import ABC, abstractmethod
-from collections.abc import Collection, Mapping, Sequence
-from dataclasses import dataclass, fields, replace
+from collections.abc import Mapping, Sequence
+from dataclasses import dataclass, replace
 from typing import TYPE_CHECKING, Any, Callable, FrozenSet, TypeVar
 from warnings import warn
 
@@ -304,9 +304,7 @@ def get_kw_pos_association(kernel):
 
 # {{{ template class
 
-# not frozen for Firedrake compatibility
-# not eq to avoid having __hash__ set to None in subclasses
-@dataclass(init=False, eq=False)
+@dataclass(frozen=True, init=False)
 class InKernelCallable(ABC):
     """
     An abstract interface to define a callable encountered in a kernel.
@@ -370,51 +368,9 @@ def __init__(self,
         def name(self) -> str:
             raise NotImplementedError()
 
-    # {{{ hackery to avoid breaking Firedrake
-
-    def _all_attrs(self) -> Collection[str]:
-        dc_attrs = {
-            fld.name for fld in fields(self)
-        }
-        legacy_fields: Collection[str] = getattr(self, "fields", [])
-        return dc_attrs | set(legacy_fields)
-
     def copy(self, **kwargs: Any) -> Self:
-        present_kwargs = {
-            name: getattr(self, name)
-            for name in self._all_attrs()
-        }
-        kwargs = {
-            **present_kwargs,
-            **kwargs,
-        }
-
         return replace(self, **kwargs)
 
-    def update_persistent_hash(self, key_hash, key_builder) -> None:
-        for field_name in self._all_attrs():
-            key_builder.rec(key_hash, getattr(self, field_name))
-
-    def __eq__(self, other: object):
-        if type(self) is not type(other):
-            return False
-
-        for f in self._all_attrs():
-            if getattr(self, f) != getattr(other, f):
-                return False
-
-        return True
-
-    def __hash__(self):
-        import hashlib
-
-        from loopy.tools import LoopyKeyBuilder
-        key_hash = hashlib.sha256()
-        self.update_persistent_hash(key_hash, LoopyKeyBuilder())
-        return hash(key_hash.digest())
-
-    # }}}
-
     def with_types(self, arg_id_to_dtype, clbl_inf_ctx):
         """
         :arg arg_id_to_type: a mapping from argument identifiers (integers for
@@ -565,8 +521,7 @@ def is_type_specialized(self):
 
 # {{{ scalar callable
 
-# not frozen, not eq for Firedrake compatibility
-@dataclass(init=False, eq=False)
+@dataclass(frozen=True, init=False)
 class ScalarCallable(InKernelCallable):
     """
     An abstract interface to a scalar callable encountered in a kernel.
@@ -744,8 +699,7 @@ def is_type_specialized(self):
 
 # {{{ callable kernel
 
-# not frozen, not eq for Firedrake compatibility
-@dataclass(init=False, eq=False)
+@dataclass(frozen=True, init=False)
 class CallableKernel(InKernelCallable):
     """
     Records information about a callee kernel. Also provides interface through
diff --git a/loopy/library/random123.py b/loopy/library/random123.py
index cde0b093a..329770e05 100644
--- a/loopy/library/random123.py
+++ b/loopy/library/random123.py
@@ -176,8 +176,7 @@ def full_name(self) -> str:
 # }}}
 
 
-# not frozen, not eq for Firedrake compatibility
-@dataclass(init=False, eq=False)
+@dataclass(frozen=True, init=False)
 class Random123Callable(ScalarCallable):
     """
     Records information about for the random123 functions.