Driving under the influence of drugs, including prescription medications, will soon carry tougher penalties in response to a recent series of traffic accidents in which drugs were a factor.

The National Police Agency said Wednesday that the Road Traffic Act will be revised to make it an offense to refuse to take a drug test, with the change set to take effect April 2.

Drivers who refuse a test will face the same punishment as those driving under the influence of drugs.

The punishment for driving under the influence of drugs, currently up to three years in prison or a fine of up to ten million won, or around six-thousand-800 U.S. dollars, will increase to as much as five years in prison or a fine of 20 million won.

Though prescription psychotropic drugs are included in the revisions, the police said the standard for punishment is whether the person’s physical condition permits the normal operation of a vehicle.