A data structure (e.g., a table) stores a listing of prefetches. Each entry in the data structure includes a respective virtual address and a respective prefetch stride for a corresponding prefetch. If the virtual address of a memory request (e.g., a request to load or fetch data) matches an entry in the data structure, then the value of a counter associated with that entry is incremented. If the value of the counter satisfies a threshold, then the lookahead amount associated with the memory request is increased.