diff --git a/cmake/podioTest.cmake b/cmake/podioTest.cmake
index f6775632c..01aa86196 100644
--- a/cmake/podioTest.cmake
+++ b/cmake/podioTest.cmake
@@ -14,6 +14,7 @@ function(PODIO_SET_TEST_ENV test)
       PODIO_USE_CLANG_FORMAT=${PODIO_USE_CLANG_FORMAT}
       PODIO_BASE=${PROJECT_SOURCE_DIR}
       ENABLE_SIO=${ENABLE_SIO}
+      PODIO_TEST_INPUT_DATA_DIR=${PODIO_TEST_INPUT_DATA_DIR}
   )
 endfunction()
 
diff --git a/python/podio/test_ReaderRoot.py b/python/podio/test_ReaderRoot.py
index a7bdf98f8..7c956f24a 100644
--- a/python/podio/test_ReaderRoot.py
+++ b/python/podio/test_ReaderRoot.py
@@ -1,6 +1,7 @@
 #!/usr/bin/env python3
 """Python unit tests for the ROOT backend (using Frames)"""
 
+import os
 import unittest
 
 from test_Reader import ReaderTestCaseMixin, LegacyReaderTestCaseMixin  # pylint: disable=import-error
@@ -19,4 +20,4 @@ class RootLegacyReaderTestCase(LegacyReaderTestCaseMixin, unittest.TestCase):
   """Test cases for the legacy root input files and reader."""
   def setUp(self):
     """Setup a reader, reading from the example files"""
-    self.reader = LegacyReader('root_io/example.root')
+    self.reader = LegacyReader(os.path.join(os.environ["PODIO_TEST_INPUT_DATA_DIR"], "v00-16-06", "example.root"))
diff --git a/python/podio/test_ReaderSio.py b/python/podio/test_ReaderSio.py
index ef7b86b6b..d8db8b9bf 100644
--- a/python/podio/test_ReaderSio.py
+++ b/python/podio/test_ReaderSio.py
@@ -1,6 +1,7 @@
 #!/usr/bin/env python3
 """Python unit tests for the SIO backend (using Frames)"""
 
+import os
 import unittest
 
 from test_Reader import ReaderTestCaseMixin, LegacyReaderTestCaseMixin  # pylint: disable=import-error
@@ -22,4 +23,4 @@ class SIOLegacyReaderTestCase(LegacyReaderTestCaseMixin, unittest.TestCase):
   def setUp(self):
     """Setup a reader, reading from the example files"""
     from podio.sio_io import LegacyReader  # pylint: disable=import-outside-toplevel
-    self.reader = LegacyReader('sio_io/example.sio')
+    self.reader = LegacyReader(os.path.join(os.environ["PODIO_TEST_INPUT_DATA_DIR"], "v00-16-06", "example.sio"))