diff --git a/bijoe/engine.py b/bijoe/engine.py
index 107d4be..73188e9 100644
--- a/bijoe/engine.py
+++ b/bijoe/engine.py
@@ -161,6 +161,8 @@ class EngineDimension(object):
                 continue
             # assert dimension.filter
             condition, values = dimension.build_filter(values)
+            if not condition:
+                continue
             with self.engine.get_cursor() as cursor:  # Ugly...
                 condition = cursor.mogrify(condition, values)
             if dimension.filter_needs_join and dimension.join:
@@ -376,6 +378,8 @@ class EngineCube(object):
                 dimension = self.dimensions[dimension_name]
                 # assert dimension.filter
                 condition, values = dimension.build_filter(values)
+                if not condition:
+                    continue
                 condition = cursor.mogrify(condition, values)
                 if dimension.filter_needs_join and dimension.join:
                     joins.update(dimension.join)