The bill, HB11, passed the Senate 47-4 on Wednesday. The House voted 98-10.
The legislation allowing online betting had been set to expire Friday. Not unexpectedly, the Illinois Racing frightened legislators with a threat that failure to sign the bill would mean limiting their oversight ability.
The three-year extension includes a surcharge on wagering.
Horse racing advocates say the fix is temporary. They pin the long-term future of the industry on allowing slot machines at racetracks so they can compete with Illinois casinos and out-of-state tracks that allow slots.