A luminaire comprising: - a lighting arrangement comprising an LED (D L ) wherein an on or off state of the LED (D L ) is controlled by a lighting control signal (S L ), and an LED lighting driver comprising: - a switched-mode power supply comprising: - an inductor connected to the lighting arrangement , wherein a current (I 6 ) through the inductor defines a current (I 2 ) through the lighting arrangement ; and - a primary control system adapted to maintain a current (I 6 ) through the inductor and lighting arrangement within a predetermined range using a switching regulator (T B , D B ); - a supplementary control system adapted to: - receive a supplementary control signal (S SUP ) indicative of a desired off-on transition of the LED (D L ); and - in response to the supplementary control signal (S SUP ) indicating a desire to switch the LED (D L ) to an on-state, override the primary control system and alter the current (I 6 ) through the inductor to a predetermined level; and a lighting control system adapted to output the lighting control signal (S L ) and, in response to the current (I 6 ) through the inductor being altered by the supplementary control system (S SUP ) and reaching the predetermined level, control the lighting control signal (S L ) so as to switch the LED (D L ) to an on-state, characterized in that the lighting arrangement further comprises a bypass transistor (T L ) connected in parallel with the LED (D L ), wherein the bypass transistor (T L ) is adapted to control a current flow in the LED (D L ) based on the lighting control signal (S L ). - a lighting arrangement comprising an LED (D L ) wherein an on or off state of the LED (D L ) is controlled by a lighting control signal (S L ), and an LED lighting driver comprising: - a switched-mode power supply comprising: - an inductor connected to the lighting arrangement , wherein a current (I 6 ) through the inductor defines a current (I 2 ) through the lighting arrangement ; and - a primary control system adapted to maintain a current (I 6 ) through the inductor and lighting arrangement within a predetermined range using a switching regulator (T B , D B ); - an inductor connected to the lighting arrangement , wherein a current (I 6 ) through the inductor defines a current (I 2 ) through the lighting arrangement ; and - a primary control system adapted to maintain a current (I 6 ) through the inductor and lighting arrangement within a predetermined range using a switching regulator (T B , D B ); - a supplementary control system adapted to: - receive a supplementary control signal (S SUP ) indicative of a desired off-on transition of the LED (D L ); and - in response to the supplementary control signal (S SUP ) indicating a desire to switch the LED (D L ) to an on-state, override the primary control system and alter the current (I 6 ) through the inductor to a predetermined level; and - receive a supplementary control signal (S SUP ) indicative of a desired off-on transition of the LED (D L ); and - in response to the supplementary control signal (S SUP ) indicating a desire to switch the LED (D L ) to an on-state, override the primary control system and alter the current (I 6 ) through the inductor to a predetermined level; and a lighting control system adapted to output the lighting control signal (S L ) and, in response to the current (I 6 ) through the inductor being altered by the supplementary control system (S SUP ) and reaching the predetermined level, control the lighting control signal (S L ) so as to switch the LED (D L ) to an on-state, characterized in that the lighting arrangement further comprises a bypass transistor (T L ) connected in parallel with the LED (D L ), wherein the bypass transistor (T L ) is adapted to control a current flow in the LED (D L ) based on the lighting control signal (S L ). <EOS>