diff --git a/tests/tests_main.py b/tests/tests_main.py
index 8bf2bae..6d91f4d 100644
--- a/tests/tests_main.py
+++ b/tests/tests_main.py
@@ -13,8 +13,7 @@ def _sh(*cmd, **kwargs):
 
 def test_main():
     """Test execution"""
-    res = _sh(sys.executable, '-c', ('\
-              import pymake; pymake.main(["-f", "%s"])' % fname).strip(),
+    res = _sh(sys.executable, '-c', f'import pymake; pymake.main(["-f", "{fname}"])',
               stderr=subprocess.STDOUT)
 
     # actual test: