An alleged meth user landed herself behind bars when she called Indiana police to rat out her drug dealer — telling cops the batch was “not what it was supposed to be.”

Sarah Harris, 34, dialed 911 twice in January to complain that she was supplied with a bad baggie of methamphetamine, an arrest affidavit obtained by the Smoking Gun shows.

Harris then allegedly handed the drugs over to cops at her home in the city of Bedford in hopes they could test their authenticity.

The bad meth left her feeling as though she were having a heart attack, she allegedly explained to police.

Harris allegedly admitted to snorting a line of the substance and felt “something different when it touched her skin and nostrils.”

She immediately knew it wasn’t the experience she signed up for — she compared the painful sensation to the “bowl of normal meth” she smoked with a friend previously, according to the documents.

Harris was apparently willing to admit to her illegal activity, as long as it meant retribution for her sketchy dealer.

“I wanted to turn the person in” that provided the bad meth, Harris allegedly declared.

For her candid honesty, Harris was slapped with a meth possession charge — a felony that carries a maximum 30-month prison sentence, according to charges filed last week.

The arrest does not mark Harris’ first run-in with cops: she has prior convictions for theft; meth possession; criminal mischief; disorderly conduct; resisting; and operating a motor vehicle while intoxicated.