diff --git a/pytato/function.py b/pytato/function.py
index c79dfcfe3349f2fe6b8d940f812b0ab3860a56b0..66a30fc1d6bd3c349a9ca1ee8628a08eb1c3b264 100644
--- a/pytato/function.py
+++ b/pytato/function.py
@@ -59,6 +59,7 @@ import enum
 import re
 from functools import cached_property
 from typing import (
+    Any,
     Callable,
     ClassVar,
     Hashable,
@@ -236,6 +237,15 @@ class FunctionDefinition(Taggable):
         else:
             raise NotImplementedError(self.return_type)
 
+    def __eq__(self, other: Any) -> bool:
+        if self is other:
+            return True
+        if not isinstance(other, FunctionDefinition):
+            return False
+
+        from pytato.equality import EqualityComparer
+        return EqualityComparer().map_function_definition(self, other)
+
 
 @attrs.frozen(eq=False, repr=False, hash=True, cache_hash=True)
 class NamedCallResult(NamedArray):