Hashmap runtime when retrieving a value

Hey there,
in this exercise (https://www.codecademy.com/paths/computer-science/tracks/cspath-cs-102/modules/asymptotic-notation/lessons/asymptotic-notation-python/exercises/hashmaps-linkedlist-runtime ) on asymptotic notations, I was asked what the runtime in big O notation for retrieving a value in a hashmap is. The correct answer was O(1), which is true if no hashmap collisions occurred before, but in the case of a collision, I feel like O(1) is not 100 % correct.
If, for example, all the hash codes of the assigned key, value pairs are the same, shouldn’t the runtime be O(n)?
I’d appreciate any answers :slight_smile: