diff --git a/src/lib/clpz.pl b/src/lib/clpz.pl
index 705ffeb7..add0f356 100644
--- a/src/lib/clpz.pl
+++ b/src/lib/clpz.pl
@@ -3586,7 +3586,7 @@ parse_reified(E, R, D,
                m(msb(A))     => [g(#A#>0) ,function(D,msb,A,R)],
                m(lsb(A))     => [g(#A#>0), function(D,lsb,A,R)],
                m(popcount(A)) => [function(D,popcount,A,R)],
-               m(sign(A))    => [function(D,sign,A,R)],
+               m(sign(A))    => [d(D), p(psign(A, R)), a(A,R)],
                m(A<<B)       => [function(D,<<,A,B,R)],
                m(A>>B)       => [function(D,>>,A,B,R)],
                m(A/\B)       => [function(D,/\,A,B,R)],