diff --git a/proofow.py b/proofow.py
index da06fb1..cd06c07 100644
--- a/proofow.py
+++ b/proofow.py
@@ -18,8 +18,8 @@ class pow_base:
         self._base = urandom(self._bits//8) if not base else base
         self._target = 2 ** (self._bits - difficulty)
 
-    def work(self, max_attempts=0):
-        cycles = count() if max_attempts == 0 else range(max_attempts)
+    def work(self, max_attempts=0, start=0, step=1):
+        cycles = count(start, step) if max_attempts == 0 else range(start, max_attempts, step)
         for nonce in cycles:
             if self.verify(nonce):
                 return nonce