diff --git a/src/plugins/e-acsl/tests/print.ml b/src/plugins/e-acsl/tests/print.ml
index 04a0d201831af165ee6c71956bc32efbbbe239da..1d084da5be994e1816fa9b02a9b0222a3f2f83c2 100644
--- a/src/plugins/e-acsl/tests/print.ml
+++ b/src/plugins/e-acsl/tests/print.ml
@@ -3,7 +3,7 @@ module Printer_extension(X:Printer.PrinterClass) = struct
   class printer = object
     inherit Printer.extensible_printer () as super
 
-    method global fmt g =
+    method! global fmt g =
       let loc, _ = Cil_datatype.Global.loc g in
       let file = loc.Lexing.pos_fname in
       if file = "" || List.exists