keepassxc/share/windows/wix-patch.xml

<?xml version="1.0" encoding="UTF-8"?>
<CPackWiXPatch>
  <CPackWiXFragment Id="CM_CP_KeePassXC.exe">
    <ProgId Id="KeePassXC.kdbx" Description="KeePass Password Database" Icon="CM_FP_KeePassXC.exe" IconIndex="1">
      <Extension Id="kdbx" ContentType="application/x-keepass2">
        <Verb Id="open" Command="Open" TargetFile="CM_FP_KeePassXC.exe" Argument="&quot;%1&quot;"/>
      </Extension>
    </ProgId>
  </CPackWiXFragment>
</CPackWiXPatch>