diff --git a/test/test_pydot.py b/test/test_pydot.py
index f15c038..4900bc1 100644
--- a/test/test_pydot.py
+++ b/test/test_pydot.py
@@ -31,7 +31,7 @@ else:
 
 
 DOT_BINARY_PATH = pydot.find_graphviz()['dot']
-TEST_DIR = './'
+TEST_DIR = os.path.dirname(__file__)
 REGRESSION_TESTS_DIR = os.path.join(TEST_DIR, 'graphs')
 MY_REGRESSION_TESTS_DIR = os.path.join(TEST_DIR, 'my_tests')