diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index d02b9561b..ee6306bdb 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -6,6 +6,7 @@ function(set_test_env _testname)
   set_property(TEST ${_testname} APPEND PROPERTY ENVIRONMENT
       LD_LIBRARY_PATH=$<TARGET_FILE_DIR:edm4hep>:$<TARGET_FILE_DIR:podio::podio>:$<$<TARGET_EXISTS:edm4hepRDF>:$<TARGET_FILE_DIR:edm4hepRDF>:>$<TARGET_FILE_DIR:ROOT::Core>:$ENV{LD_LIBRARY_PATH}
       ROOT_INCLUDE_PATH=${PROJECT_SOURCE_DIR}/edm4hep:${PROJECT_SOURCE_DIR}/utils/include:$ENV{ROOT_INCLUDE_PATH}
+      PYTHONPATH=${PROJECT_SOURCE_DIR}/python:$ENV{PYTHONPATH}
   )
   set_tests_properties(${_testname} PROPERTIES
     FAIL_REGULAR_EXPRESSION "[^a-z]Error;ERROR;error;Failed"