Modify reason in Diversion Header

Diversion: <sip:1234@1.1.1.1>;reason=follow-me;privacy=off;screen=yes

 

I need to match reason=follow-me and replace it with reason=unconditional

 

sip-manipulation
        name                                    test
        description
        split-headers
        join-headers
        header-rule
                name                                    test1
                header-name                             Diversion
                action                                  manipulate
                comparison-type                         case-insensitive
                msg-type                                request
                methods                                 INVITE
                match-value
                new-value
                element-rule
                        name                                    test2
                        parameter-name
                        type                                    header-value
                        action                                  replace
                        match-val-type                          any
                        comparison-type                         case-insensitive
                        match-value                             reason=follow-me
                        new-value                               reason=unconditional

 

No go, any pointers?