diff --git a/stack_orchestrator/repos/setup_repositories.py b/stack_orchestrator/repos/setup_repositories.py
index 29f05bb0..3612aed0 100644
--- a/stack_orchestrator/repos/setup_repositories.py
+++ b/stack_orchestrator/repos/setup_repositories.py
@@ -249,7 +249,7 @@ def command(ctx, include, exclude, git_ssh, check_only, pull, branches, branches
             error_exit(f"stack {stack} does not exist")
         with stack_file_path:
             stack_config = yaml.safe_load(open(stack_file_path, "r"))
-            if not "repos" in stack_config:
+            if "repos" not in stack_config:
                 error_exit(f"stack {stack} does not define any repositories")
             else:
                 repos_in_scope = stack_config["repos"]