A method of transmitting an Orthogonal Frequency Division Multiplexing, OFDM, symbol having a guard interval including a cyclically repeated part of an original symbol comprises applying a guard interval for the OFDM symbol, the guard interval including a first part, where the first part is a cyclic prefix, including an indication whether the applied guard interval has a second part, wherein the second part is a cyclic prefix and/or postfix, applying, when indicated to be present, the second part of the guard interval, and transmitting the OFDM symbol. A method of receiving the symbol, transmitter, receiver and computer programs for implementing the methods are also disclosed.