A microwave ablation probe, comprising: an applicator arranged to apply microwave radiation to heat surrounding tissue; a feed cable (104, 204, 304, 404, 504) arranged to supply electromagnetic energy to the applicator; a tubular shaft arranged to house at least part of the length of the feed cable; a coolant flow path (108, 110, 308, 310, 408, 410, 508, 510) via which coolant is able to flow, the coolant flow path being located within a space between the tubular shaft and the feed cable; and a choke arranged to reduce power reflected from the applicator along the feed cable, wherein: the choke comprises one or more bridging structures (114a, 114b, 114c, 214a, 214b, 214c, 214a', 214b', 314a, 314b, 414a, 414b, 514a, 514b) each provided on a component of the tubular shaft or the feed cable, the one or more bridging structures being arranged to extend across the space between the tubular shaft and the feed cable and form an electrical connection therebetween, the one or more bridging structures each extend only part way around a longitudinal axis of the ablation probe, thereby allowing coolant to flow through the choke, and the one or more bridging structures are each formed from an angled region cut out from a wall of the component of the tubular shaft or the feed cable from which they are formed. an applicator arranged to apply microwave radiation to heat surrounding tissue; a feed cable (104, 204, 304, 404, 504) arranged to supply electromagnetic energy to the applicator; a tubular shaft arranged to house at least part of the length of the feed cable; a coolant flow path (108, 110, 308, 310, 408, 410, 508, 510) via which coolant is able to flow, the coolant flow path being located within a space between the tubular shaft and the feed cable; and a choke arranged to reduce power reflected from the applicator along the feed cable, wherein: the choke comprises one or more bridging structures (114a, 114b, 114c, 214a, 214b, 214c, 214a', 214b', 314a, 314b, 414a, 414b, 514a, 514b) each provided on a component of the tubular shaft or the feed cable, the one or more bridging structures being arranged to extend across the space between the tubular shaft and the feed cable and form an electrical connection therebetween, the one or more bridging structures each extend only part way around a longitudinal axis of the ablation probe, thereby allowing coolant to flow through the choke, and the one or more bridging structures are each formed from an angled region cut out from a wall of the component of the tubular shaft or the feed cable from which they are formed. the choke comprises one or more bridging structures (114a, 114b, 114c, 214a, 214b, 214c, 214a', 214b', 314a, 314b, 414a, 414b, 514a, 514b) each provided on a component of the tubular shaft or the feed cable, the one or more bridging structures being arranged to extend across the space between the tubular shaft and the feed cable and form an electrical connection therebetween, the one or more bridging structures each extend only part way around a longitudinal axis of the ablation probe, thereby allowing coolant to flow through the choke, and the one or more bridging structures are each formed from an angled region cut out from a wall of the component of the tubular shaft or the feed cable from which they are formed.