Type checking fails when a sensitive parameter is autoloaded from hiera (no automatic conversion)

Puppet Version: 5.4.0
Puppet Server Version: N/A
OS Name/Version: CentOS 7

When a class parameter is set to use the sensitive type, automatic class parameter lookup fails with a type checking error.

Desired Behavior:

The value stored in hiera should be automatically validated against the datatype specified within Sensitive[], or not type-validated if the inner type was not specified.

Actual Behavior:

Error: Evaluation Error: Error while evaluating a Function Call, Class[Cntlm]: parameter 'cntlm_password' expects a value of type Undef or Sensitive[String], got String (file: /tmp/modules/cntlm/examples/init.pp, line: 2, column: 5) on node localhost.localdomain

Workaround:

Remove the value as a class parameter, and use Sensitive(lookup()) within the body of the class.