Kourtney Kardashian‘s 11-month-old son Mason had his first run-in with peanut butter over the weekend — and it did not go well.

Mason Dash Disick was rushed to the hospital after he sampled peanut butter for the first time and had a major allergic reaction.

Kourtney posted on her blog:

“Friday night Mason ate some peanut butter and had a little allergic reaction to it,”

“He threw up within minutes of tasting it and got hives on his face. I called 911 and the fire department came immediately.”

Kourtney said that the firemen instructed her to get her little man further medical care, so they took Mason to the emergency room of the local hospital.

“They suggested that we take him to the hospital, so we did,”

“He was in good spirits the whole time and didn’t even know anything was wrong. He even enjoyed riding in the ambulance. He’s such a good boy!!”

Every first time mom will experience scary moments with their children, but Kourtney says she’s learned the power of a mother’s instinct:

“I learned such a lesson with this … to always follow my instincts and call 911. Always better safe than sorry.”

We’re glad Mason is doing okay!