diff --git "a/claudetool/onstart/testdata/\321\200\321\203\321\201\321\201\320\272\320\270\320\271.py" "b/claudetool/onstart/testdata/\321\200\321\203\321\201\321\201\320\272\320\270\320\271.py"
new file mode 100644
index 0000000..8110369
--- /dev/null
+++ "b/claudetool/onstart/testdata/\321\200\321\203\321\201\321\201\320\272\320\270\320\271.py"
@@ -0,0 +1,2 @@
+# Python file with Russian characters in filename
+print('Hello from русский.py')