diff --git a/.gitignore b/.gitignore
index e3c95b9..30ee945 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,4 +9,6 @@ env
 /*.egg-info/
 /.idea
 /build
-/daffodil/*.c
\ No newline at end of file
+/daffodil/*.c
+*~
+*.so
\ No newline at end of file
diff --git a/daffodil/hstore_predicate.pyx b/daffodil/hstore_predicate.pyx
index ca9a8bb..aa6661f 100644
--- a/daffodil/hstore_predicate.pyx
+++ b/daffodil/hstore_predicate.pyx
@@ -22,7 +22,7 @@ def forces_optimizer(children):
         return False
 
     return all(
-        isinstance(expr, ExpressionStr) and expr.daff_test == "?="
+        isinstance(expr, ExpressionStr) and expr.daff_test == "?=" and expr.daff_val == True
         for expr in children
     )
 
diff --git a/test/tests.py b/test/tests.py
index 0e82a84..c0ae589 100644
--- a/test/tests.py
+++ b/test/tests.py
@@ -567,6 +567,15 @@ def test_timestamp_notin(self):
             )
         """)
 
+    def test_or_nonexistence(self):
+        self.assert_filter_has_n_results(4, """
+            num_of_sat_test_takers = 50
+            [
+                non_existing ?= false
+                non_existing_too ?= false
+            ]
+        """)
+
 
     #def test_comparing_a_string_containing_int(self):
     #    self.assert_filter_has_n_results(417, """