diff --git a/zipline/test_algorithms.py b/zipline/test_algorithms.py
index e4d9b559..0d2a158b 100644
--- a/zipline/test_algorithms.py
+++ b/zipline/test_algorithms.py
@@ -274,8 +274,8 @@ def uses_ufunc(data, *args, **kwargs):
 
 
 @batch_transform
-def price_multiple(data, multiplier, keyarg=1):
-    return data.price * multiplier * keyarg
+def price_multiple(data, multiplier, extra_arg=1):
+    return data.price * multiplier * extra_arg
 
 
 class BatchTransformAlgorithm(TradingAlgorithm):
@@ -383,24 +383,24 @@ class BatchTransformAlgorithm(TradingAlgorithm):
 
         # check that calling transforms with the same arguments
         # is idempotent
-        self.price_multiple.handle_data(data, 1, keyarg=1)
+        self.price_multiple.handle_data(data, 1, extra_arg=1)
 
         if self.price_multiple.full:
             pre = len(self.price_multiple.ticks)
-            result1 = self.price_multiple.handle_data(data, 1, keyarg=1)
+            result1 = self.price_multiple.handle_data(data, 1, extra_arg=1)
             post = len(self.price_multiple.ticks)
             assert pre == post, "batch transform is appending redundant events"
-            result2 = self.price_multiple.handle_data(data, 1, keyarg=1)
+            result2 = self.price_multiple.handle_data(data, 1, extra_arg=1)
             assert result1 is result2, "batch transform is not idempotent"
 
             # check that calling transform with the same data, but
             # different supplemental arguments results in new
             # results.
-            result3 = self.price_multiple.handle_data(data, 2, keyarg=1)
+            result3 = self.price_multiple.handle_data(data, 2, extra_arg=1)
             assert result1 is not result3, \
                 "batch transform is not updating for new args"
 
-            result4 = self.price_multiple.handle_data(data, 1, keyarg=2)
+            result4 = self.price_multiple.handle_data(data, 1, extra_arg=2)
             assert result1 is not result4,\
                 "batch transform is not updating for new kwargs"
 
diff --git a/zipline/transforms/utils.py b/zipline/transforms/utils.py
index cac1c119..7b47d9f7 100644
--- a/zipline/transforms/utils.py
+++ b/zipline/transforms/utils.py
@@ -520,14 +520,18 @@ class BatchTransform(EventWindow):
         if self.compute_only_full and not self.full:
             return None
 
+        recalculate_needed = False
         if self.updated:
             # Create new pandas panel
             self.window = self.get_data()
             # reset our counter for refresh_period
             self.trading_days_since_update = 0
+            recalculate_needed = True
+        else:
+            recalculate_needed = \
+                args != self.last_args or kwargs != self.last_kwargs
 
-        args_changed = args != self.last_args or kwargs != self.last_kwargs
-        if self.updated or args_changed:
+        if recalculate_needed:
             self.cached = self.compute_transform_value(
                 self.window,
                 *args,