An Iranian asylum seeker who smuggled 1.8 kilograms of opium into Melbourne through the mail claimed the package was for personal use.
Behrus Miri Kalaniki had a one gram-a-day addiction, which meant the almost $1 million package would have taken him up to five years to get through.
He pleaded guilty to attempting to posses the drug, and had his bridging visa cancelled when he was charged in October last year.
County Court Judge Carolyn Douglas described Kalaniki's plan to smuggle the drug into Australia in rubber rolls hidden inside car parts as "sophisticated".
But Judge Douglas found it difficult to believe Kalanaki's claims that he planned to use the entire package for personal use.
"Opium loses its form over time, so that amount wouldn't last 900 days - even if you were to share it. And as a regular user you would know that," the judge said on Thursday.
She did accept his one gram-a-day addiction led to his poor decisions.
The judge said the Werribee resident, supported by his wife in court, began smoking opium in Iran before he illegally arrived in Australia by boat from Indonesia.
Kalaniki sought refuge in Australia because he feared persecution in Iran for his family's links to the Kurdish Democratic Party.
He started using the drug again because he was "feeling bored and frustrated" at being unable to work - a condition of his bridging visa.
Kalaniki was sentenced to 10 months in jail with no parole period - less than the 373 days he has already spent in pre-sentence custody.
Despite already serving his sentence, Kalaniki won't walk free, with both the judge and his lawyer conceding he will be released into the custody of immigration officials.
His defence counsel Colin Ham said his client would go "straight to (detention centres in) Maribyrnong or Nauru".