ifclass syntax within if statement

[Bob Apodaca]

When installing AMD64 systems, I have created a small script:
#!/bin/sh

if ifclass AMD64 ; then
    # https://wiki.debian.org/Multiarch/Implementation
    $ROOTCMD dpkg --add-architecture i386
fi

However, when the target system is installed it appears the command has 
not run:

# dpkg --print-foreign-architectures

I would appreciate any suggestions.