diff --git a/test/conftest.py b/test/conftest.py
index b54e253..b8b7a0f 100644
--- a/test/conftest.py
+++ b/test/conftest.py
@@ -1,6 +1,7 @@
+from pycallgraph import PyCallGraph, Config
 import tempfile
 
-from helpers import *
+import pytest
 
 
 @pytest.fixture(scope='module')
diff --git a/test/helpers.py b/test/helpers.py
index 4ea4abb..0bbee37 100644
--- a/test/helpers.py
+++ b/test/helpers.py
@@ -1,13 +1,6 @@
 # flake8: noqa
 import time
 
-import pytest
-
-import fix_path
-from pycallgraph import *
-from pycallgraph.tracer import *
-from pycallgraph.output import *
-
 
 def wait_100ms():
     time.sleep(0.1)
diff --git a/test/test_color.py b/test/test_color.py
index 0d33fc5..535a577 100644
--- a/test/test_color.py
+++ b/test/test_color.py
@@ -1,4 +1,6 @@
-from helpers import *
+from pycallgraph import ColorException, Color
+
+import pytest
 
 
 def test_bad_range():
diff --git a/test/test_config.py b/test/test_config.py
index 5d5335f..ce0cbc2 100644
--- a/test/test_config.py
+++ b/test/test_config.py
@@ -1,4 +1,4 @@
-from helpers import *
+from pycallgraph.config import Config
 
 
 def test_init():
diff --git a/test/test_gephi.py b/test/test_gephi.py
index 15dd708..f3f2dfa 100644
--- a/test/test_gephi.py
+++ b/test/test_gephi.py
@@ -1,5 +1,10 @@
-from helpers import *
-from calls import *
+from pycallgraph import PyCallGraph
+from pycallgraph.output.gephi import GephiOutput
+import os
+
+import pytest
+
+from calls import one_nop
 
 
 @pytest.fixture
diff --git a/test/test_graphviz.py b/test/test_graphviz.py
index 35d8d8e..2669aed 100644
--- a/test/test_graphviz.py
+++ b/test/test_graphviz.py
@@ -1,5 +1,10 @@
-from helpers import *
-from calls import *
+from pycallgraph.output.graphviz import GraphvizOutput
+from pycallgraph.pycallgraph import PyCallGraph
+import os
+
+import pytest
+
+from calls import one_nop
 
 
 @pytest.fixture
diff --git a/test/test_output.py b/test/test_output.py
index 9149e5c..6b17775 100644
--- a/test/test_output.py
+++ b/test/test_output.py
@@ -1,4 +1,5 @@
-from helpers import *
+from pycallgraph import Config
+from pycallgraph.output import Output
 
 
 def test_set_config():
diff --git a/test/test_pycallgraph.py b/test/test_pycallgraph.py
index bdc7dc4..76a2fba 100644
--- a/test/test_pycallgraph.py
+++ b/test/test_pycallgraph.py
@@ -1,4 +1,7 @@
-from helpers import *
+from pycallgraph.exceptions import PyCallGraphException
+from pycallgraph.tracer import AsyncronousTracer, SyncronousTracer
+
+import pytest
 
 
 def test_start_no_outputs(pycg):
diff --git a/test/test_script.py b/test/test_script.py
index 0aa9016..fad47e1 100644
--- a/test/test_script.py
+++ b/test/test_script.py
@@ -1,7 +1,5 @@
 import subprocess
 
-from helpers import *
-
 
 def execute(arguments):
     command = 'PYTHONPATH=. scripts/pycallgraph ' + arguments
diff --git a/test/test_trace_processor.py b/test/test_trace_processor.py
index bdf16cc..7b8a0cf 100644
--- a/test/test_trace_processor.py
+++ b/test/test_trace_processor.py
@@ -1,9 +1,11 @@
+from pycallgraph.tracer import TraceProcessor
 import re
 import sys
 
-from helpers import *
-import calls
-from pycallgraph.tracer import TraceProcessor
+import pytest
+
+from pycallgraph import Config
+from calls import one_nop, nop
 
 
 @pytest.fixture
@@ -20,7 +22,7 @@ def test_empty(trace_processor):
 
 def test_nop(trace_processor):
     sys.settrace(trace_processor.process)
-    calls.nop()
+    nop()
     sys.settrace(None)
 
     assert trace_processor.call_dict == {
@@ -32,7 +34,7 @@ def test_nop(trace_processor):
 
 def test_one_nop(trace_processor):
     sys.settrace(trace_processor.process)
-    calls.one_nop()
+    one_nop()
     sys.settrace(None)
 
     assert trace_processor.call_dict == {
@@ -45,7 +47,7 @@ def stdlib_trace(trace_processor, include_stdlib):
     trace_processor.config = Config(include_stdlib=include_stdlib)
     sys.settrace(trace_processor.process)
     re.match("asdf", "asdf")
-    calls.one_nop()
+    one_nop()
     sys.settrace(None)
     return trace_processor.call_dict
 
diff --git a/test/test_util.py b/test/test_util.py
index 084c6f3..bf8cf09 100644
--- a/test/test_util.py
+++ b/test/test_util.py
@@ -1,4 +1,4 @@
-from helpers import *
+from pycallgraph.util import Util
 
 
 def test_human_readable_biyte():