The invention relates to a needle safety device for a medical device, the needle safety device comprising: a base portion having a bore extending along a longitudinal center axis therethrough for receiving a needle; and two opposing jaws extending from the base portion generally in the axial direction and each having a head portion in the region of its free end, wherein the needle safety device includes a locking projection for securing the needle safety device to the medical device. The needle safety device according to the invention further provides at least one elastic element mounted to the jaws in a non-surrounding manner lateral to the center axis in a region between the base portion and the head portions, wherein at least one elastic element and the jaws are configured such that the jaws can be spread apart against a restoring force of at least one elastic element in order to allow the needle received in the bore to extend all the way through the needle safety device.