diff --git a/src/lib/CoAlgFormula.ml b/src/lib/CoAlgFormula.ml
index 8d50b9a357a3517302baf67122cf8a10eacb16a6..dcc1856aff5bb0cf56a3d25744fec5ba666f0846 100644
--- a/src/lib/CoAlgFormula.ml
+++ b/src/lib/CoAlgFormula.ml
@@ -774,8 +774,8 @@ let rec verifyMuGuarded unguarded formula =
   | ENFORCES (_,a) | ALLOWS   (_,a)
   | MIN (_,_,a)    | MAX (_,_,a)
   | ATLEASTPROB (_, a) | LESSPROBFAIL (_, a)
-  | MORETHAN (_,_,a) | MAXEXCEPT (_,_,a) -> proc a
-  | ID(a) -> proc a
+  | MORETHAN (_,_,a) | MAXEXCEPT (_,_,a) -> verifyMuGuarded [] a
+  | ID(a) -> verifyMuGuarded [] a
   | NORM(a, b) | NORMN(a, b) -> (proc a; proc b)
   | CHC (a,b)  -> (proc a ; proc b)
   | FUS (_,a) -> proc a