A method of increasing the hydrogen/carbon monoxide (H2/CO) ratio in a syngas stream derived from a carbonaceous fuel including coal, brown coal, peat, and heavy residual oil fractions, preferably coal. The fuel-derived syngas stream is divided into at least two sub-streams, one of which undergoes a catalytic water shift conversion reaction. The so-obtained converted sub-stream is combined with the non-converted sub-stream(s) to form a second syngas stream with an increased H2/CO ratio. The method of the present invention can provide a syngas with a H2/CO ratio more suitable for efficient hydrocarbon synthesis carried out on a given catalyst, such as in one or more Fischer-Tropsch reactors, as well as being able to accommodate variation in the H2/CO ratio of syngas formed from different qualities of feedstock fuels.