diff --git a/platformio/util.py b/platformio/util.py
index 4f59b983..9f728128 100644
--- a/platformio/util.py
+++ b/platformio/util.py
@@ -138,8 +138,12 @@ class memoized(object):
                 self.cache[key] = (time.time(), func(*args, **kwargs))
             return self.cache[key][1]
 
+        wrapper.reset = self._reset
         return wrapper
 
+    def _reset(self):
+        self.cache = {}
+
 
 class throttle(object):