Easiest just to change your export to test whether to set PERL5OPT: 
    if `perl -MInternal::Module -e0 2>/dev/null`; then export PERL5OPT
+=-MInternal::Module; fi

[download]
Though possibly you want PERL5OPT="-MInternal::Module $PERL5OPT" in case the env var is being used for something else too?

In reply to Re: Is it possible load optional modules from PERL5OPT? by ysth
in thread Is it possible load optional modules from PERL5OPT? by Anonymous Monk

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