A Northern California city is asking residents not to use T-shirts as toilet paper as panicked customers exhaust toilet paper aisles nationwide in response to the coronavirus.

“COR Wastewater Management responded to a sewer backup from shredded t-shirts being used in place of toilet paper,” the City of Redding tweeted Thursday. “Remember, if you use anything other than toilet paper, Bag it. Don’t flush it.”

Wastewater management employees worked Wednesday night to clear the strips of T-shirt behind the clog at a lift station, according to the Redding Record Searchlight.

Officials warned that just because something will flush, it doesn’t mean it will pass through the system. Paper towels, tissues, napkins, rags and disposable wipes, even those that advertise as being “flushable,” can damage and clog lines, sending sewage back up into peoples’ homes.

For anyone forced to use something other than toilet paper, the city has one request: “bag it.”