diff --git a/travis_run_tests.sh b/travis_run_tests.sh
index 0b27cff..cd4a606 100644
--- a/travis_run_tests.sh
+++ b/travis_run_tests.sh
@@ -10,7 +10,7 @@ rst2html5 --strict CHANGELOG.rst > /dev/null
 
 # first test module from installed wheel
 python -m pip install $(ls -1t dist/pycalver*.whl | head -n 1)
-grep 'coding: utf-8' $(python -c 'import pycalver;print(pycalver.__file__)')
+grep 'coding: utf-8' $(python -c 'import pycalver;print(pycalver.__file__.replace(".pyc", ".py"))')
 python -m pytest test/
 
 if [[ $(python -c "import sys;print(sys.version[:3])") == "3.7" ]]; then