diff --git a/zipline/pipeline/filters/filter.py b/zipline/pipeline/filters/filter.py
index c184e0d6..63138cbc 100644
--- a/zipline/pipeline/filters/filter.py
+++ b/zipline/pipeline/filters/filter.py
@@ -167,6 +167,10 @@ class Filter(RestrictedDTypeMixin, ComputableTerm):
     output of a Pipeline and for reducing memory consumption of Pipeline
     results.
     """
+
+    # make filters window safe
+    window_safe = True
+    
     ALLOWED_DTYPES = (bool_dtype,)  # Used by RestrictedDTypeMixin
     dtype = bool_dtype