diff --git a/esmvaltool/utils/recipe_test_workflow/Jinja2Tests/file_exists.py b/esmvaltool/utils/recipe_test_workflow/Jinja2Tests/file_exists.py
index 9478b0d140..760d16495a 100644
--- a/esmvaltool/utils/recipe_test_workflow/Jinja2Tests/file_exists.py
+++ b/esmvaltool/utils/recipe_test_workflow/Jinja2Tests/file_exists.py
@@ -1,5 +1,6 @@
 from pathlib import Path
 
+
 def file_exists(file_path):
     run_directory = Path.cwd()
     site_recipes_file_path = run_directory / file_path