diff --git a/grep/generate_files_with_problematic_names b/grep/generate_files_with_problematic_names
index af0cf2a..adb2809 100644
--- a/grep/generate_files_with_problematic_names
+++ b/grep/generate_files_with_problematic_names
@@ -33,7 +33,7 @@ echo "fwpn:blank as separator:meyer" > "blank as separator.txt"
 echo "fwpn:newline as separator:mayer" > "newline_as
 separator.txt"
 echo "fwpn:tabulator as separator:mayr" > tabulator_as$'\t'separator.txt
-echo "fwpn:with questionmark:meier" > with_?.txt
+echo "fwpn:with questionmark:meier" > "with_?.txt"
 echo "fwpn:colon:meyer" > with_:.txt
 
 exit 0
\ No newline at end of file