Mind the gap: micro-expansion joints drastically decrease the bending of FIB-milled cryo-lamellae

•Micro-expansion joints greatly increase the cryo-FIB-milling success rate.•These lateral gaps milled in the support prevent cryo-lamellae bending and breaking.•They provide physical buffers to absorb support material motion during milling.•They are easy to implement and compatible with the rest of the cryo-ET workflow.