Fiscal deficits have been put forward as the main factor in the occurrence of currency crises by the first‐generation currency crisis models. While most papers within this framework consider a fiscal deficit that occurs with certainty, in reality an increase in the government's fiscal burden may be an uncertain outcome. This paper introduces a model where there is uncertainty about the occurrence of a fiscal deficit for a finite number of periods, and studies the effects of such uncertainty on the evolution of currency crises. If the fiscal deficit materializes, the government has to abandon the fixed exchange rate regime, as in the standard case. However, the paper shows that the peg becomes unsustainable even if the fiscal deficit never materializes. Therefore, a speculative attack occurs and the fixed exchange rate regime collapses with the mere possibility of a deficit, independently of whether this outcome actually occurs or not.