Hi Aleksey, xmlsec now request function xmlBuildQName which is missing in libxml2 2.4.x. Other problem is that test "merlin-xmldsig-twenty-three/signature" fail with libxml2 versions 2.6.2 and 2.6.6. Note: same test succeed for xmlsec-1.2.4 and libxml2-2.4.30 What about your build envirionment ? Regards, Roumen