
We have tried wooden mattresses and they don't fit Seams are good sewn up, the mattress is not soft, which is very important to me in terms of baby's sleep safety! As another reviewer mentioned, I bought the mattress topper shown in the photo and it fits perfectly.

TILLYOU Sleep Sack - Sleeveless Quilted Sleeping Bag Baby, Fits Infants Newborns Age 18-24 Months, Grey Stripes
31 Review

2.5 TOG Cotton Toddler Sleep Sack With Feet For Winter, Long Sleeve Baby Wearable Blanket For 2T-3T Weighted Sleep, Comfortable Sleep Sacks With Legs
39 Review

Baby Floral Fitted Crib Sheet For Boy And Girl Toddler Bed Mattresses Fits Standard Crib Mattress 28X52 (Pink Mint Floral)
29 Review

Yoofoss Baby Crib Sheets 2 Pack: Super Soft Microfiber for Standard Crib and Toddler Mattress, Blue-Gray - Perfect for Boys and Girls
29 Review

MaidMAX Cube Storage Bins, Foldable Fabric Storage Container With Handles For Closet, Laundry, Home And Office, Wood Grain Print, Set Of 6
41 Review

Pampers diapers New Baby Dry 2, 4-8 kg, 94 pcs., white
87 Review

COSYLAND Nursery Step Stools For Children - Safe And Sturdy Tower Helper With Anti-Drop Railing And Non-Slip Mat
32 Review

Large Toy Box Chest For Boys & Girls - 24.5"X13" X16", Flip-Top Lid, Divider, Collapsible Storage Bins For Nursery, Playroom, Closet & Living Room | Homyfort (Black)
39 Review