diff --git a/dedupe/variables/exists.py b/dedupe/variables/exists.py
index 00ca7eb4..72887255 100644
--- a/dedupe/variables/exists.py
+++ b/dedupe/variables/exists.py
@@ -5,11 +5,10 @@
 from categorical import CategoricalComparator
 
 from dedupe._typing import PredicateFunction
-from dedupe.variables.base import DerivedType
-from dedupe.variables.categorical_type import CategoricalType
+from dedupe.variables.base import DerivedType, FieldType
 
 
-class ExistsType(CategoricalType):
+class ExistsType(FieldType):
     type = "Exists"
     _predicate_functions: list[PredicateFunction] = []
 
diff --git a/tests/test_exists.py b/tests/test_exists.py
new file mode 100644
index 00000000..f4129ef3
--- /dev/null
+++ b/tests/test_exists.py
@@ -0,0 +1,13 @@
+import unittest
+
+import numpy
+
+from dedupe.variables.exists import ExistsType
+
+
+class TestExists(unittest.TestCase):
+    def test_comparator(self):
+        var = ExistsType("foo")
+        assert numpy.array_equal(var.comparator(None, None), [0, 0])
+        assert numpy.array_equal(var.comparator(1, 1), [1, 0])
+        assert numpy.array_equal(var.comparator(1, 0), [0, 1])