diff --git a/src/expression/expr/arithmetic.py b/src/expression/expr/arithmetic.py
index 60200c9..d903dcb 100644
--- a/src/expression/expr/arithmetic.py
+++ b/src/expression/expr/arithmetic.py
@@ -30,7 +30,6 @@ def evaluate(self):
 class Div(Binary):
     def evaluate(self):
         l, r = self.left.evaluate(), self.right.evaluate()
-        assert r != 0
         return l / r
 
 
diff --git a/tests/test_evaluate.py b/tests/test_evaluate.py
index 0b761e4..f40dcee 100644
--- a/tests/test_evaluate.py
+++ b/tests/test_evaluate.py
@@ -1,8 +1,6 @@
 from unittest import TestCase
 
 from expression.evaluate import evaluate
-from expression.expr.arithmetic import Constant, Div, Add, Mul
-from expression.expr.parse import parse
 
 
 class TestEvaluate(TestCase):
diff --git a/tests/test_expression.py b/tests/test_expression.py
index 88eb839..f980a6c 100644
--- a/tests/test_expression.py
+++ b/tests/test_expression.py
@@ -3,7 +3,7 @@
 from expression.expr.arithmetic import Constant, Div, Add, Mul
 
 
-class TestMiddle(TestCase):
+class TestExpr(TestCase):
     def test_constant(self):
         term = Constant(0)
         self.assertEqual(0, term.evaluate())
diff --git a/tests/test_parse.py b/tests/test_parse.py
index e978a7e..8a4d0ff 100644
--- a/tests/test_parse.py
+++ b/tests/test_parse.py
@@ -4,7 +4,7 @@
 from expression.expr.parse import parse
 
 
-class TestMiddle(TestCase):
+class TestParse(TestCase):
     def test_parse_constant(self):
         term = parse("0")
         self.assertIsInstance(term, Constant)