SharePoint 2013 Workflow Manager problem

I am in the process of building a test SharePoint 2013 farm.

I have a 3 node, load balanced workflow manager farm.

SharePoint farm consists of the following: 3 WFE's, load balanced. 2 Application servers. 2 Index Servers

I have been following the instructions from Spencer Harbar located here: http://ift.tt/17fb2Zx

I have exported the certificate from the wfm web site and used these 2 commands to create a new SPTrustedRootAuthority $trustCert = Get-PfxCertificate "C:\wfm.cer" New-SPTrustedRootAuthority -Name "WF Manager Farm" -Certificate $trustCert

I get almost all of the way to the end and when I issue this command Register-SPWorkflowService -SPSite "https://portal.com" -WorkflowHostUrl "https://wfm.com"

I receive this error: The root of the certificate chain is not a trusted root authority.

How do I resolve this error?