diff --git a/stl/ast.py b/stl/ast.py
index 2c08252..eec5a62 100644
--- a/stl/ast.py
+++ b/stl/ast.py
@@ -1,11 +1,12 @@
 # -*- coding: utf-8 -*-
-
 from collections import deque, namedtuple
 from functools import lru_cache
 
 import funcy as fn
 from lenses import lens, bind
 
+import stl
+
 
 def flatten_binary(phi, op, dropT, shortT):
     def f(x):
@@ -47,6 +48,9 @@ class AST(object):
 
         return phi
 
+    def __call__(self, trace, time):
+        return stl.pointwise_sat(self)(trace, time)
+
     @property
     def children(self):
         return tuple()
diff --git a/stl/test_boolean_eval.py b/stl/test_boolean_eval.py
index f98ce77..47429e8 100644
--- a/stl/test_boolean_eval.py
+++ b/stl/test_boolean_eval.py
@@ -1,6 +1,6 @@
 import hypothesis.strategies as st
 import traces
-from hypothesis import given, settings, Verbosity, Phase
+from hypothesis import given
 from pytest import raises
 
 import stl
@@ -81,11 +81,6 @@ def test_eval_smoke_tests(phi):
 
 
 @given(SignalTemporalLogicStrategy)
-@settings(
-    max_shrinks=0,
-    verbosity=Verbosity.verbose,
-    perform_health_check=False,
-    phases=[Phase.generate])
 def test_temporal_identities(phi):
     stl_eval = stl.boolean_eval.pointwise_sat(phi)
     stl_eval2 = stl.boolean_eval.pointwise_sat(~phi)
@@ -124,6 +119,12 @@ def test_fastboolean_smoketest():
         stl.fastboolean_eval.pointwise_sat(stl.ast.AST())
 
 
+def test_callable_interface():
+    phi = stl.parse(
+        '(G[0, 4](x > 0)) & ((F[2, 1](AP1)) | (AP2)) & (G[0,0](AP2))')
+    assert not phi(x, 0)
+
+
 def test_implicit_validity_domain_rigid():
     phi = stl.parse('(G[0, a?](x > b?)) & ((F(AP1)) | (AP2))')
     vals = {'a?': 3, 'b?': 20}