diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 7f39e19..9ba7fb0 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -32,7 +32,7 @@ foreach (PYTHON_TEST_FILE ${PYTHON_TEST_FILES})
     # Add the test
     if (${ENABLE_COVERAGE})
         message (STATUS "${PYTHON_TEST_NAME} test will run with code coverage")
-        add_test (NAME ${PYTHON_TEST_NAME} COMMAND coverage run -m unittest ${PYTHON_TEST_NAME})
+        add_test (NAME ${PYTHON_TEST_NAME} COMMAND coverage run -a -m unittest ${PYTHON_TEST_NAME})
     else ()
         add_test (NAME ${PYTHON_TEST_NAME} COMMAND python -m unittest ${PYTHON_TEST_NAME})
     endif ()