diff --git a/proofow.py b/proofow.py
index ac20b9c..da06fb1 100644
--- a/proofow.py
+++ b/proofow.py
@@ -26,7 +26,7 @@ class pow_base:
         raise RuntimeError('Failed to find a nonce in {} iterations!'.format(max_attempts))
 
     def verify(self, nonce):
-        hexresult = self._hexdigest(self._base + str(nonce).encode())
+        hexresult = self._hexdigest(self._base + str(nonce).encode('ascii'))
         return int(hexresult, 16) < self._target
 
     def export(self):
@@ -35,7 +35,7 @@ class pow_base:
     @classmethod
     def load(cls, export):
         difficulty, base = export.split(':', 1)
-        return cls(int(difficulty), b64decode(base.encode()))
+        return cls(int(difficulty), b64decode(base.encode('ascii')))
 
 
 class pow_hashlib_base(pow_base):