diff --git a/test/my-rdbg-tuning.ml b/test/my-rdbg-tuning.ml
index 2af25aff3fcff54dfc6b071e5e8fe73b38cf9839..5154741c23da14634a86b660f6eb6893175ff3e8 100644
--- a/test/my-rdbg-tuning.ml
+++ b/test/my-rdbg-tuning.ml
@@ -436,9 +436,11 @@ let pdf_viewer =
   if Sys.command "which zathura" = 0 then "zathura" else
   if Sys.command "which xpdf" = 0 then "xpdf" else
   if Sys.command "which acroread" = 0 then "acroread" else
-  if Sys.command "which evince" = 0 then "evince" else
-    Printf.printf "Warning: no pdf viewer is found to visualize %s\n%!" dotfile
-
+  if Sys.command "which evince" = 0 then "evince" else (
+    Printf.printf "Warning: no pdf viewer is found to visualize %s\n%!" dotfile;
+    "ls"
+  )
+  
 let _ = 
   !dot_view ();
   let cmd = Printf.sprintf "%s sasa-%s.pdf&" pdf_viewer dotfile in