diff --git a/src/lib/clpz.pl b/src/lib/clpz.pl
index dc12e7a9..20674469 100644
--- a/src/lib/clpz.pl
+++ b/src/lib/clpz.pl
@@ -1902,12 +1902,6 @@ label([], _, Selection, Order, Choice, Optim0, Consistency, Vars) :-
                          retractall(extremum(_)))
         ).
 
-retractall(What) :-
-        (   \+ \+ retract(What) ->
-            retractall(What)
-        ;   true
-        ).
-
 % Introduce new variables for each min/max expression to avoid
 % reparsing expressions during optimisation.